Lee
This is a wonderful gun, although you are going to have to find a correct pair of grips
for it ! Its good that the invoice could be found, so that the engraving and nickel
cylinder could be confirmed.
I think the gun is a 4-screw 1905, or saying it another way, an early 1905. With the
square butt, its a 1905 - no doubt about that. A couple of my early 1905's have
lettered as 4-screw 1905's. These configurations were made between serial numbers
58000 and 62450, plus maybe a few after that. The problem is that they are intermixed
with the round butts, in the same serial number series, so the number made is unknown.
I'm aware of at least 8 to 12 4-screw 1905's .
Here is a gun I have, that is similar to yours, but not completely factory original.
Serial number is 37577 - its a round-butt 1902 1st change target. Unfortunately the
invoice is not available, but it was a special order; the letter speculates that it was
the engraving. Further communications from the historian says that the engraving is
either Oscar or Eugene Young.
The gun went back to the factory in 1919, presumably to have the cylinder nickel
plated and the studs and screw nickel plated. Also, the extractor rod assembly was
replaced at that time.
These next pictures show details of the engraving.
This next picture, with a bit of squinting, shows the individual chisel cuts. They are very tiny cuts.
This next picture is an end-view of the cylinder. It shows the finishing replating stamp - a P inside of
a circle.
This last image is the factory letter.
Regards, Mike Priwer