I have a Springfield 1842 musket, with a very similar family story. My mother's great grandfather was a Civil War vet, and when a small child, mom's family visited him on occasion, and my mom remembered seeing this 90yo man carrying large sacks of livestock feed on his shoulder. I remember hauling around sacks of cracked corn in my youth, and they weighed 80#!
The musket hung in the rafters of a shed behind our house for many years. At some point, the nipple had been removed with a hacksaw or file, but other than that, it was in nice exterior condition. A local man drilled-out the old nipple and installed a modern replacement, and I got a replica ramrod from Dixie. I have no proof that great-great-grandpa carried that particular musket, and no way to find out. Still, it sits above my mantle today, and hopefully will for generations to come.
Numrich/Gun Parts or Dixie would probably have parts, either original or newly made, to repair your rifle. The mechanisms are very simple, and it would be pretty easy to determine what was amiss.