The Ref. 5512 from 1959 has pretty much almost everything we might look for on the current Submariner. Its case had grown to 40mm, up within the 37mm to 38mm of earlier pieces. Crown-guards ended up additional, along with the bezel now a little overhung the aspect of the case https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/