Omega Seamaster Cal.505 18ct, 1958 ‘Tropical’ Dial


100% Genuine & All Original

Fully Inspected, Serviced & Guaranteed

A Very Carefully Owned and Lightly Used Example

Robust 34mm Diameter Case, Excluding the Omega Crown

Beautiful Original, Unrestored Two-Tone ‘Tropical’ Golden Brown Dial

Chronometer Grade Cal.505, 20 Jewel Automatic Movement in Top Condition

Heavy 18ct Solid Yellow Gold Three Piece Case with Beautiful Sweeping Lugs

Matching Vintage Omega Presentation Box Included, as Shown

New Tan Crocodile Strap and Gold Plated Buckle

VGWL 12 Months Written Warranty Included*

VGWL Lifetime Authenticity Guarantee

Free Worldwide FedEx Delivery

Free UK Special Delivery

Sold 28th May '20
VGW Reference: Om785
Price £3,500 Sold


Out of stock

Add to favourites heartRemove from favourites heartADD TO FAVOURITES
DO YOU HAVE A WATCH LIKE THIS TO SELL?Add to favourites heart

Omega Watches

Since the company was founded in 1848, Omega has pioneered a huge range of innovations. Britain’s Royal Flying Corps chose Omega watches in 1917 as official timekeepers for its pilots and again in 1940, RAF Pilots watches were supplied by Omega. The 1940s also saw the first tourbillon wristwatch and the first of the famous Seamaster watches, whilst the ’50s and ’60s introduced the legendary Constellation, Speedmaster, Seamaster 300 and Railmaster. Over these years, everyone from John F. Kennedy to Elvis wore Omega watches on official duties. What’s more, in 1962, astronaut Wally Schirra took his Omega Speedmaster to space on NASA’s Mercury Sigma 7 mission and in 1969 two Omega Speedmasters landed on the moon, worn by Neil Armstrong and Buzz Aldrin.


The Omega Seamaster was first released in 1948 and has been a cornerstone of the Omega collection in continuous production ever since. The Seamaster was introduced as a sporty dress watch, however, due to its popularity and success, diver versions were later introduced in the 1970s. The Seamaster Ploprof was used by Jacques Cousteau in a series of experimental dives to depths of around 500 metres.

Here we have an Omega Automatic dress watch from 1958, with an original, unrestored dial, in 18ct gold and in wonderful condition. The watch features a most attractive  3, 6, 9 ‘Explorer’ type dial, which is beautifully balanced and elegant. The watch case is a good size at 34mm, excluding the correct Omega signed crown. This watch also has a very high-grade highly accurate Cal.505 movement (see below), which along with the rest of this beautiful watch, is in pristine sparkling condition!

The two-tone dial is preserved in excellent overall condition and has turned a tropical golden yellow and brown over the years. This is very probably because of a reaction between the compounds used in the dial and external factors such as humidity, heat or exposure to the sun. A uniform patina such as this is a rarity, and therefore highly sought-after by collectors.

The Dial

The 3 – 6 – 9 dial is referred to as the ‘Explorer’ dial. It is a classic design of the period, one of our favourites and very popular. Here it has a wonderful sense of balance, style and elegance. Applied gilt numerals and ‘arrowhead’ hour indices on a two-tone golden yellow and brown dial are matched with original Dauphine hands and a centre sweep seconds hand, both in beautifully restored condition.

The dial is signed with the applied gold Omega brand and ‘Omega Automatic’ with ‘Swiss Made’ at the very bottom of the dial.

This dial is original, unrestored and untouched. It is also in really excellent condition considering the age of the watch, with even fading, only a little spotting and an even overall tropical patina. Due to its relatively good condition and for reasons of retaining the character and the originality of the watch, we have left it completely alone. If however, you would prefer the dial sympathetically restoring, we will be happy to arrange this for you free of charge.

The lens is the original and has the tiny Omega branding embedded in its very centre. It is very clear with no scratches and so we have not replaced it as we often do when restoring an Omega Seamaster.

Please note, even though our photographer has done excellent work, the dial does look much better face to face in real life.

The Movement

This Omega Calibre 505, 20 Jewels, Chronometer grade movement was Omega’s first full rotor automatic, as opposed to the earlier ‘Bumper’ automatic movement which had been used until this point.

As can be seen, the original Omega high-grade Cal.505 20 Jewels, beryllium bronze automatic movement is totally pristine following full an overhaul and service by our vintage Omega specialist watchmaker. The movement is signed ‘Omega Watch Co.’ ‘Swiss’ and ‘Twenty 20 Jewels’ with the serial number 16029694 which dates manufacture to 1958. The movement winds, runs & sets smoothly and is working perfectly and keeping excellent time.

These high grade Cal.501 movements are very highly regarded for their accuracy and reliability, making this watch perfectly suitable for everyday use. This watch has just been fully overhauled and serviced by our watchmaker and is calibrated to run arrow straight within +1 second / day! This is no exaggeration and it is the most accurate we have seen on a 1950s Omega movement this year. This is truly outstanding for any watch and particularly amazing for a watch of this age. This movement also has a 46 hour power reserve when fully wound. The automatic winding mechanism is very efficient and if worn regularly each day this watch will never need winding. We therefore have total confidence in offering this Omega with our 12 months on the movement*.

*Please note – our 12 months’ warranty is only included if the list price is paid.

The Case

The very heavy and chunky original high-grade 18ct yellow gold 3 piece press-fit case is in superb condition indicating this watch has only ever seen very light and careful use. The lines and edges are all crisp and well defined and there are no signs of damage and no scratches, dings or other blemishes visible to the naked eye. The case-back is also in beautiful condition and has never been inscribed. This is an early Omega Seamaster, therefore the case-back does not have the Seamaster motif as this was introduced in around 1960.

This is a British market Omega Seamaster watch case made by Dennison in England for Omega. Dennison was a top quality watch case manufacturer based in Birmingham UK who made watch cases for many Swiss watch manufacturers including Rolex, Jaeger-LeCoutre, Longines, Zenith etc.

The case measures a large 34mm in diameter, excluding the Omega signed crown.

The case is of full-thickness and has never been inscribed.

Inside the case-back bears the Omega Watch Co. triangle branding along with ‘Dennison, Made In England’, and Birmingham 18ct .750 1958 hallmarks. It also carries the case serial number 742526.

As ever, our standard advice applies: Vintage watches should be kept clean and dry at all times.

The Strap & Buckle

A new, high quality, tan crocodile strap has been fitted, along with a gold plated buckle. However, if a different colour or style of strap is preferred, please let us know and we will do our best to oblige free of charge. We carry tan, chestnut, dark brown and black in stock in plain padded leather, crocodile skin or lizard skin. We can also obtain most types and colours of strap at short notice from our partners Watch Obsession. Please take a look at their fabulous range and if you see something you prefer we will be happy to fit this for you and have your watch on its way to you within two business days!

The Box and Papers

Although there are no original papers with this watch, all the numbers and markings on the watch are correct, dating the watch to 1958.

Our detailed ‘Particulars’ document will be included in the sale, along with our detailed receipt and 12 months warranty*. A separate insurance valuation for the replacement value of this watch will also be provided at the time of sale, along with our unique ‘Lifetime Authenticity Guarantee’ which states: “If at any time, this watch proves to be anything less than totally authentic, or not as described, Vintage Gold Watches of London will offer you a full refund at any time”.

The presentation box shown in the photographs will be included with this watch. However, if this is not required, we will be able to reduce the price of the watch by quite a few £s. Please enquire.

In Conclusion

This is a superb example of the iconic Omega Seamaster automatic watch with the Calibre 505 movement which is of a very high grade and on a par with watches far more expensive than this. Indeed when new, this watch would have cost more than the equivalent Rolex. Omega Seamaster watches are highly collectable and the rarity of this watch means the value will always remain strong.

This watch will also make an excellent investment and family heirloom piece. Even though vintage Omega prices have risen markedly recently, we feel fine examples such as this still remain undervalued. As each year goes by and the world market for vintage watches expands, availability will become more limited, so prices are surely destined to climb ever higher!

A word about our prices – We always try our hardest to acquire the very highest quality watches we can find, before restoring them to the highest possible standards. We then offer these at the fairest prices we can, taking into account our pre and post-sales care and service. This approach inevitably means we will never be the cheapest, but nor will we be the most expensive. Indeed there are a number of well-known stores in West London which are very successful, charging between two to three times the price you see here. We therefore consider our prices to be fair, given the quality of watches we have to offer.

We are happy to accept PayPal as this is the quickest method of payment. However, if you would wish to pay by bank transfer, we will be pleased to pass on a 3% transaction saving to you. Similarly, if you wish to pay by International SWIFT or International Bank Wire Transfer, we will provide you with our BIC / Swift number and our IBAN number.

Please note, we welcome part exchanges and if you have a watch, or small collection for sale, please contact us as we will be happy to discuss.

We will be happy to Service your watch, Repair your watch or Restore your watch, all at ‘sensible’ prices. Please see here.

If you have any questions, please call us on 020 7727 7095 or if calling from overseas on +44 207 727 7095.

We are here, ready, available and awaiting your call! We will be happy to answer any questions and offer advice about this or any of our watches listed for sale. If you would like some general advice regarding any aspect of vintage watches, including buying, selling, or collecting vintage watches, we will also be happy to hear from you.

Finally, please enjoy some time spent viewing our other fine vintage gold watches.

Thank you.