The OP sent me the pictures. They're larger and somewhat easier to see, but still pretty blurry.
Jim says the early 52 had a large dovetail on the receiver bridge for the sight.
It doesn't like like any 52 sight I've ever seen, but I found a very early catalog drawing of a 52, and it does appear to sit in a dovetail.
But... Even at that early stage the 52 sight appears to have had windage adjustment knobs on the rear base, which this sight doesn't have.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.