The Ref. 5512 from 1959 has just about almost everything we'd try to look for on The existing Submariner. Its situation had grown to 40mm, up through the 37mm to 38mm of earlier parts. Crown-guards have been included, as well as the bezel now a little bit overhung the side https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/