Okay, I don't have any clue at all what this has to do with anything, but the Sharps is back up and running. I hadn't gotten the hammer quite tight against the lock plate, so I put it in the vice this morning (leather on both sides to protect things, naturally) and tightened it down. Don't think I got it quite as far as it initially was, but the hammer's hitting the cone squarely again.
But the set trigger's now working.
Tried it a couple times by hand, and then 'fired" it half a dozen times with leather to protect the cone. She's working fine. And I don't have the faintest clue what any of it had to do with anything, unless
something realligned in the actual lock that I jarred out of place when I pulled the hammer. But visually there is no difference, so I'm completely baffled.
This was literally hours before I was going to take it to a local gunsmith - it was bugging me, so I decided not to wait for season's end.
Calum