It's great you have the letter showing it was shipped "soft", meaning it was planned to be engraved all along. That is a second best for an engraved gun, first being factory engraved.
It's hard to tell if this is the original finish though, or if it has been re-finished at some time. The serial numbers look buffed and a couple other areas, in your photos anyway.
Value is somewhat difficult - you ask 3 experts and you'll get 3 different ideas. Mostly a "range". I'm not going to do that, don't know enough. But it's fairly valuable with that letter, even if redone sometime in the past.
It's hard to tell if this is the original finish though, or if it has been re-finished at some time. The serial numbers look buffed and a couple other areas, in your photos anyway.
Value is somewhat difficult - you ask 3 experts and you'll get 3 different ideas. Mostly a "range". I'm not going to do that, don't know enough. But it's fairly valuable with that letter, even if redone sometime in the past.