amanico[JLC Moderator]
372462
Rolex Submariner Big Crown Ref 5510.
Produced about only one year, in 1958, and maybe, in 1959, the Submariner Ref 5510 is one of the most elusive Big Crown reference with the 6200, and the Tudor 7922 / 7924.
Which explains we don't see it every day.
Here is one of them. Credit picture: Antiquorum.

Serial Number 361 833, from 1958.
Best,
Nicolas