Dating vintage benrus watches
The 1940's watch styles were very similar to the styles of the 30's. A few years following the end of WWII america entered a period of prosperity, economic growth, and technical advancements in electronics and science. Many (but not all) watches were affected by the vision of the future. 1960's watches were a little bigger than they had been before.
These watches are typical of the "Deco" style of the teens and 20's.By the late 1930's mens watches were more masculine. This was made possible by the advent of square movements.Until then all movements were round, limiting the designs.These numbers are stamped on the back (outside) of the case. The code was usually stamped on the back of the watch case.If there is no two symbols, it could be that your watch was made before 1948. For exabple, If you have a Bulova watch with the stamp M3 then it was made in 1963.