Vintage Omega ID and Info Super Challenge

Could you please provide me any information on this vintage yellow gold Omega watch. I inherited this item many years ago, and am not looking to sell it, just to gain intel of any kind. Works when wound up. I had it serviced at an authorized Omega repair shop in San Francisco at 210 Post St around 1993. The rather distinguished looking intake guy advised me it was valuable, but didn’t comment any further. While in my possession It has not been opened otherwise. The watch originally belonged to my great uncle (b:1894) who was a dual citizen, importer/exporter out of NYC, and who spent a lot of time in Europe and especially Switzerland. He died in 1984 and I carry-on luggaged his ashes, which were surprisingly heavy for an old man of small stature, to 112 deg summertime Florence so he could be buried next to his sister. There was no air conditioning. Funnily enough, British Airways did not check his passport although I was prepared just in case. He spoke 7 languages, wore the original Aqua de Parma, had lots of money and no kids, ate Kretschmer’s Wheat Germ every day, and did calisthenics into his mid 80’s. Attached is a photo of him while a member of the Austro-Hungarian Army. I have searched Google, but I’m unable to find a watch that matches, in particular with the numbers at the even stations and slashes otherwise. There is one on EBAY that looks similar, but in Rose gold and the hands are different (it is listed as RARE Vintage 18K Rose Gold Omega ref 2685 cal.266.35.5mm) I don’t know if it is just the difference in band placement/style, but my watch has particularly esthetic lugs. Thank you for your expertise.