I would simply have asked him to replace the stock. He is a nebish (disabled vet or not) if he didn't observe on the first pin removed that he blew out wood, and did it to all of the pin locations.
Anyway..., back to the thread..., on the Bess the lock was routinely removed and serviced by soldiers. Don't be afraid of unshipping the lock and removing the parts for rust inspection and cleaning. You don't have to do it every time, but it's a pretty good idea to do it 2x a year. Like the pins..., keep track of where each screw belongs, and a main spring vice is a good tool to have, for the main spring and frizzen spring. Also pay attention to the upper surface of the frizzen spring and the frizzen cam where it contacts the frizzen spring, and the frizzen screw itself. Corrosion in those places can really mess with reliability.
I would first work on rust removal on the bolts rather than replacement, as normally it takes a great deal of rust to render them into the replacement category.
I have found a "green scrubbie" to be a bit harsh for the exterior surface of the barrel, and the yellow colored ones sold for removing carbon from the surface of a ceramic stove-top are less abrasive, and seem to me to give you a result much closer to 18th century brick dust and oil (what the soldiers used). I have also had to use 600 and 1500 grit wet/dry emory paper with baby oil to remove stubborn staining of the steel for folks who wanted that done when overhauling several misused muskets. Some folks like the "patina" and some don't.
LD