Thanks for the additional pictures. I think that the barrel was replaced,
and when that was done, the gun was reblued. This doesn't change
anything about the gun, but its what I think.

The primary indicator of this is the serial numbers that are stamped
under the barrel. That, in my view, is not the right stamping, for the
1903 - 1904 period. When the gun was originally made, the stamping
dies used were very fine, and small, and produced very lightly
stamped digits. They were also in a very straight line.

The present serial number stamping is exactly the opposite. The
digits do not lie in a straight line, and the are stamped very deeply.
This is much more like the stampings of the late 1940's .

I would presume that the factory had some extra spare-parts barrels
from this period. This is because this barrel has the dual-caliber
stamping. Maybe it was an extra one from 1903, and was already
blued, although I doubt it. Rather I would think that it needed to be
blued, after fitting it to this frame, and to make the colors match,
they probably refinished the entire gun.

The marking on the rear grip strap is not factory. Someone did that
decoration; I have no idea as to who, when, or where.

Regards, Mike Priwer