Just picked up a 98% condition 1952 (208xxx) Winchester 70 300 h&h magnum a few weeks ago. From 1952-54, the Monte Carlo stock version came with the Marbles 69 rear sight.
I think this is the only time period a Marbles sight was used on a Pre 64 Model 70.
Post some pictures man!!!
I have a 375 H&H that's like that.. from "54-56"... Receiver from '56 and the barrel from a '54...
. Oh wait, you were talking about the rear sights for the monte carlo rifles. The 16B was also used from '54 to '63. It replaced the marbles sight during that time..