This is a second generation Railmaster from the 1960s that was officially supplied to American railroad companies. The word “OFFICIAL” is written at the 6 o’clock position on the dial, indicating that it is an official product. The movement is equipped with the 500 series, the second generation automatic caliber with full rotation and bidirectional winding that appeared in 1958. Ref.165.002/SS (35mm diameter) Automatic (Cal.550) / Made in 1965 and discontinued shortly because sued by Ball Watch Company and therefore much rarer than first and third generation .

This sn 23471145 dated 1966 and 1966 also written in case back . Note a movie shows ( can’t attach here ) has another version called Railroad but mistake type T SWISS T as should be Swiss Made ( very rare too ) and for Canada market. This watch accurate as Railway watch must be. With military strap ( actually has military version for railmaster ). 35 mm . Watch only . Very Rare and collection item . Price firmed.

https://wannabuyawatch.com/product/omega-railmaster-ref-165-020-circa-1968/