I would dismount that lock and spray it off with some compressed cleaner like Gun Scrubber and then brush the life out of it with an old toothbrush and a bronze brush. You may need to take some wet/dry very fine emory cloth to the frizzen face and shine it up real brite. Spray it up good with Rem Oil and don't worry about getting it on the frizzen. When you go for a shooting session wipe down the pan and frizen face with soem rubbing alcohol and punch out the flash hole with a pip cleaner. Also, you may want to take a look at web sites dedicated to ML shooting and maintainance. Oil and grease are as much a part of flintlocks as powder, patch and ball.