Regards the Silar lock; as far as the internals go you can use Jim's lock "right out of the box," or, go to the trouble of lightly tuning it which in my shop chiefly involves polishing the inside the lock plate and all bearing surfaces, anything that is metal to metal should be slick as snot (and greased). You want to use a light touch with either stones or fine paper wrapped about something like popsicle sticks (600, 800, 1200 & 3000 followed by a green oxide final polishing). You do not want to alter the internal geometry at all, and I would leave the tumbler shaft as is except for a very light going over with a 800 grit paper, you do not want to create any slop between the shaft and its hole. Polish the heads of the screws, generally done utilizing a drill press and paper backed with a stiffener.
The outside, of course, needs light filing and finishing so you remove the gray bead blasted surface, and the small pits lurking beneigh it. I generally begin with a Gorbet brand #2 file and the use medium and fine carborundum papers - to take it down to a polish use regular but finer paper. Go light with the file(s), let them do their job, Keep the surface clean and try and not create more work by scoring the locks surfaces, clean the files often. Finish the outside according to the look and degree you want for the gun at hand, it is rare to go beyond 400 grit paper, 320 is generally as far as I go.
Regards forestock shaping: Taylor said it best.
dave