Interesting to see, at 12, his .22 Browning Model B take-down has the scope secured to the barrel rather than the action.
I had one of similar vintage (not as fancy a grade) and had endless trouble getting it to hold its zero with a scope.
Eventually the penny dropped (as did the scope) when a friend was shooting it and the scope hopped off the factory “grooved” receiver.
It was less a dovetail, more like two parallel walls, and the retention could not cope with the sharp rap of the bolt cycling just below.
I stuck a peep sight on the wrist and it worked fine until I replaced it with the left handed first model T-Bolt that has given me good service for over 50 years.
My Father bought the Remington version of that gun, the 241 Remington Automatic .22, in 1947, shortly before he joined the USMC. As a kid growing up in St. Paul, MN during the war, he had lots of different after school and weekend jobs, and a nice nest egg for a good rifle, when he was a teenager.
He used the gun the way it came for 50 years, until he could no longer see the sights. It got the same, cantilever scope mount, up on the barrel. Dad was a rifleman, and had a clear grasp of what would work, and that was really the only option for a takedown gun.
My opinion, that design and the takedown Browning Automatic .22 that came much later, aren’t the best design to maximize accuracy. Probably why Robert had the semiauto Marlin with a 4X scope, the model 60 Marlin that my brother has custody of, at the moment, is more accurate than the Remington.
Best,
Ted