Almost any gun is repairable but as Jim says, economically ?. No! I just spent close to 100 hours restoring and to a large extent re-creaing a Colt 1861 Navy Conversion. Got ripped off buying it from a lying seller, it had misfit parts from other guns and parts missing. I made from scratch a base pin, complete ejector and loading gate. Luckily I have an original one that I could copy. Some parts I bought repros & made the grip. Result now is a respectable "ole brown gun" worth nowhere near what I would have charged a client.
Interesting about repro parts, in recent months I bought 9 parts from Dixie and Numrich said to fit Colt 1860 Army & '51 - '61 Navy. Not one part could be installed without work, let alone fit it to function. All had holes too small, too large or mislocated, too wide, incorrect contour, or for wrong kind of gun. They apparently expect the Italian repro parts to interchange with Colt and/or with other Itie repro guns. I pity old Joe Sixpack trying to fix his gun without tooling and ability.
If anyone cares, I put my logo (which is a registered trade mark) on it in several places. See pix.