The Ref. 5512 from 1959 has almost all the things we would search for on The existing Submariner. Its case had grown to 40mm, up from the 37mm to 38mm of previously items. Crown-guards were being included, as well as the bezel now somewhat overhung the aspect of the case https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/