Thanks again for the additional comments!
David (Price), fortunately I have this activity as a luxury rather than a necessity. I'm just a hobbyist, though a serious one, and my livelihood doesn't depend on doing this work. Hope you have good results with your rifles in "tough shape"--look forward to seeing what you can do with them!
Singlemalt, I was inspired to restore the pictures of the fowler I made in the spring of 2016, which had been held hostage by photobucket. Here is a link to that post, if you're interested.
http://americanlongrifles.org/forum/index.php?topic=40169.msg389357#msg389357A couple of things I didn't mention in the first post--after replacing the missing wood pieces, the light-colored patches were stained with LMF Lancaster maple and ebonizer to match the old wood as closely as possible before using tinted Tried and True oil varnish and bone black to even out the color into the original wood. Luckily, the original stock was quite dark in color and fairly easy to match.
Also, after removing the old drum and nipple, I found an unplated steel bolt of the same size and screwed it tightly into the existing hole, then cut off the excess with a hacksaw and files. I tried to peen the edges of the new bolt even with the old barrel, but the bolt was made of pretty tough stuff that didn't peen too well. I roughed it up by beating it with 60-grit sandpaper and browned it coarsely with LMF browning/degreaser, but the round ring still showed. I didn't try to weld it or permanently fix it so that it could be removed in the future if necessary. Touchhole was drilled through the plug with a 1/16 drill bit and the entry hole roughed up a bit.
I also engraved the current date on the inside of the lock and the sideplate just to keep everything honest!
Thanks again, all,
Gregg