Howdy
Regarding the firing pin "puckering up" a little crater as it passes through the recoil shield.
This is the recoil shield of an Uberti Cattleman that I bought used around 2000 or so.
This is the recoil shield of a Colt.
When the hammer falls on a Colt Single Action Army, or any of its replicas, the firing pin "finds its way" through the hole in the frame. This is because the firing pin follows an arc as it passes through the frame, but the hole for the firing pin is drilled perpendicular to the frame. That is why the firing pin on most SAA revolvers or their replicas are pinned into the hammer, and free to wiggle up and down a little bit.
The steel of the firing pin is harder than the steel of the frame, so as the firing pin flashes through the frame it tends to peen the metal of the frame a little bit. This can cause a burr to rise up around the firing pin hole.
Colts, on the other hand have a hardened insert pressed into the frame, to prevent this problem. No burr will be raised from the hardened insert.
I had an Uberti Cattleman years ago that suffered so badly from this problem that the cylinder bound up when loaded, and would not turn, because of interference with the primer on a live round in the cylinder. I eventually got rid of that revolver. I still have one Uberti Cattleman, the photo is of its recoil shield. Simply filing down the raised burr did not solve the problem, the burr returned. So I went in through the barrel with a long drill bit and very carefully turned it by hand, creating a bit of a countersink around the hole. This worked because any subsequent burr simply rose up into the countersink. What you see in the photo is a little bit of 'chatter' caused by the drill bit, leaving some unsightly marks, but this solution worked for a long time.
bsparker83 mentioned the color case hardening and brass catching his eye. I assume you mean a brass trigger guard and back strap. If you care, Colt never used a brass trigger guard or back strap on the Single Action Army. Also, Uberti does not use real bone Case Hardening, what you see is a chemically applied finish.
Other than that, I like my Cattleman well enough, although I like my real Colts a little bit better. I bought this Cattleman used around 2000. It is chambered for 45 Colt.