Omega Seamaster 165/6.5003 Dennison Case Acquisition

Andrew (aroma) shares a thrilling acquisition story, detailing his meticulous process of identifying a rare Omega Seamaster. His post highlights the importance of keen observation and deep historical knowledge in vintage watch collecting, especially when dealing with online auctions and imperfect listings. This piece offers valuable insights into the pursuit of elusive references and the satisfaction of a successful, high-stakes bid.

To be honest, I nearly passed this one by – and who could blame me when you see the photos that accompanied it on the well known auction site recently.  It looked filthy with a marked dial but there was something that grabbed my attention: 

 A gold Seamaster is not such a rare beast – a 165/6.5003 cal 562 - but I could tell that this one was English cased – either by Dennison or Shackman & Sons – and so worth a second glance.

On the caseback photo I could just about make out the Dennison format of numbering and could just read the case serial number – 459376.  That number started alarm bells ringing as it is the highest serial number in my Dennison database and signified that it was one of the very last produced before Dennison’s went out of business in Feb 1967.  As such, it should have a Birmingham ‘R’ hallmark and is as rare as the proverbial hen’s teeth – and I have been looking for a good one for some years.  I have only seen 2 other Birmingham ‘R’ hallmarks on a Dennison cased Omega and both were prohibitively expensive.  The movement serial was right also at 23.86 million (1966/7)

So, do I take a chance or not?  Looking at the dial photos I believed that the marks were shadows or reflections of graunch marks on the crystal so it was worth a punt.

 I hate bidding on this internet auction site – everything seems to rocket up in price within the last few seconds and I’ve been out manoeuvred several times by cannier bidders.  So I waited until the last 6 seconds and pressed the button with my (hopefully) killer blow.  Wow!! I got it but my hand was definitely trembling.

 Then comes the wait and all the doubts – fortunately though it was delivered within two days and to my intense relief it is a corker.  Yes it will need a new crystal and a thorough clean and service but the dial is first rate and that’s my criteria for a collectable watch.

Dennison’s made cases for several of the big names in horology and their gold cases are very high quality – much heavier than corresponding Swiss equivalents.  By the end of the 1950s it seems that Dennison stopped making silver, stainless steel and gold/chrome plated cases to concentrate on the gold ones.  Dennison’s production of gold cases averaged around 65,000 per year every year from the end of WW2 until 1966 (over 1.3 million in total).  Then suddenly production ceased rapidly – between May 1966 and their demise in Feb 1967 they only produced 9,000 odd cases.  So something went seriously wrong (I wish I knew what) then – maybe Omega, who were Dennison’s mainstay, gave the contract to Shackman & Sons (who produced cased for Omega well into the 1970s/80s – who knows

Cheers

Andrew