If it's an early 50's I don't think it will be stamped 36. That started in 55 I think. Looks like a pre 36 flat latch. A friend paid $450 at last weeks show for the same gun except the hammer wasn't bobbed like that one.
Neat older flat latch, likely pre model numbered as others have said. Yours looks well used judging by the bluing, possible hammer mod?, and wear on the grips. I inherited on in very nice shape in its box and was surprised to find it wasn’t worth all that much, maybe $5-$600 tops. My personal opinion on yours is $350-$450. Just my 2 cents
I have a 12” steel plate hanging 70yds out from the back door that I can hit most of the time with mine, I gave $100 for it about 20 years ago, it looks like sin but I feel very calm while it’s in my right front pocket