Hi Larry,
Often cast parts look like that and need to be cleaned up. All of Chambers locks need the internal parts polished and stoned. They all have casting seams, cast texture, and rough edges that need to be removed or cleaned up. When you get a Chambers lock the inside of the plate has been ground flat, the edge faces of the tumbler are ground, and the outside of the bridle (not the inside that matters) is ground smooth. Nothing else. For the other manufacturers you don't even get that. All the casting seams remain, the sear usually shows no polishing at all on any surface. The good news is the castings are superb and usually fit very well but they can all benefit from cleaning up and polishing. The only locks you can buy that do not need to be worked on at all are Chris Laubach's. Even Jim Kibler's locks should have the cast texture and any casting seams polished away on the parts that are cast if you want something that looks historically correct. Having written all that, I also understand that many of the parts needing attention are hardened and tempered. That makes cleaning them up a pain in the butt because you cannot file them except with diamond files and stones. I have no problem because I routinely anneal everything, clean, fit, and polish it up, and then harden and temper the components.
Anyway, the nose of that sear needs to be filed flat with a diamond file or stone but then you may find the change causes the sear bar to drop lower on the lock plate. Then you may need to adjust your trigger. Everyone reading this post remember this really, really well. You can rarely do just one thing to a flintlock. Every change usually results in some other unexpected issue. You have to understand the mechanism as a system with every component linked in a network. Change one thing, and you will likely have to change something else.
dave
