OK, that tells all.
That's a .357 Magnum, which later became the Model 27.
The screw in the top of the side plate means that it was made prior to.... (guides are at home, this is out of my potential faulty memory banks), 1954?
Model number stamping started in 1957.
Given the condition of the logo on the right side, it's definitely an aftermarket satin nickel or similar finish.
OK, I see where you say it's Armaloy.
Pity, because if it were in the original blue, it would probably command something of a premium.
"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.