Identifying a vintage Omega watch - help please

Hi, my Father has an Omega watch inherited from his brother in 1971 (its his daily wear watch). I have been trying to identify the model, as it has no model name on the dial, just Omega and Automatic, on a champagne-like colour face with a date box at position 3.
Today we have taken the back off and seen the code 166.002 which appears to indicate it's a Seamaster, and on the internals it says SEVENTEEN - 17 Jewels - Unadjusted
I have attached photo of the face, purists, please don't be too aghast at the scratches on the crystal, as I said it is his daily wearer for over 53 years!
Various articles I have read seem to imply that from the introduction of the Seamaster, Omega put the model names on the dial face. I am convinced this is 100% original because of the amount of time he has owned it.
His late brother also left me an original Zodiac Sea Wolf from the 1960s, so wasn't one for adulterating watches either.
Any help would be much appreciated
Thanks, Gary

It looks like I have found the exact same model being advertised on Ebay. This is being advertised as a rare (only 3,000 approx. made) and the rarity is the 17 jewel movement I believe. My question had been.....is it really a Seamaster if it doesn't have the name on the face, but this seems to support that it could be. Thanks for your responses.
Dad almost threw this away a few years ago!! 🤦

Get it serviced and a crystal polish. Tan or black leather band. Depends on causal or dress