Gene,
Thanks for the patent info. That's very helpful.
Actually, I misquoted Stroebel. He wrote "The No. 47 and No. 52 were discontinued by 1955." Since 1932 is earlier than 1955 he is technically correct. I suspected they were discontinued long before 1955.
There are probably a couple of reasons that the No. 47 is not often seen on a No. 1A or 2A SA. If one was buying a new sight and wanted one that is windage adjustable, one would probably just buy a No. 29 1/2 or 30 1/2 which was introduced about the same time. I suspect the cost difference would be negligible. Later, when receiver sights became available, most would probably go that route.
