Hi Bill,
I hope that you didn't lose too much in the 2019 data. Been there and done that, it's not a happy thing...
For the Sharps, I don't think it's the mating of the original and Ped parts. I bought the rifle back in 2013 (I think you shared the original sale post that I bought it from), and it's worked flawlessly since. According to the original ad, all of the lock internals are Pederosoli, so only the mainspring is original. Because one of the first things that I did was to replace the mainspring with an original back then, because I've developed a distrust of modern ones. And it's only been misbehaving since last fall, so it's definitely "something wrong" not something occasional like humidity.
The Ped mainspring is in my Garrett lock, which just sits on a shelf, since the Garrett had an original lock in it when I got it. So if the lock mortice clearance check doesn't turn anything up, I may try dropping the Ped mainspring back in. But I really don't think that will impact. If it comes to that, I hope that I'm wrong.
Thanks,
Mike