Jeremiah,
Thanks, glad you like the rifle.
I can't answer about how common they were on originals. I'm sure others here know more than I on that subject.
The one I saw on an original, in a museum display in Tennessee long ago, was fastened onto the barrel with what looked like copper rivets that had possibly been staked to the barrel, then peened after passing through holes in the rib. The ram rod was missing on the one I saw but the rifle was in a glass case so I couldn't see it really well.
They will probably hold up just fine. The only danger I can see is if the ram rod should be left hanging a bit past the muzzle and hook on something, it could split the rib.
It is a bit lighter than a metal rib but in the unlikely event that I make another half stock TN rifle, I would probably go with a metal rib. I spent way too much time on making and attaching the wooden one, but then, I am very slow!
Ted