The Ref. 5512 from 1959 has just about all the things we would seek out on The existing Submariner. Its situation had grown to 40mm, up from your 37mm to 38mm of earlier pieces. Crown-guards were being additional, as well as bezel now slightly overhung the facet of the case https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/