The Ref. 5512 from 1959 has nearly all the things we would try to find on The existing Submariner. Its situation had grown to 40mm, up from the 37mm to 38mm of earlier pieces. Crown-guards were extra, along with the bezel now a little overhung the aspect of the case https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/