Are these "flies"flat with a hole drilled thru for a separate pin??? I tried that early and abandoned them for one with the pin as part of the fly.
I know what worked for my lock making.MAKING a lock,even the most bonehead basic types as seen on a lot of American guns that are revered relics now requires machinist,tool makers,blacksmith and filing skills.Springs are a separate category and using spring steel of known benefit is a must.Guessing and wondering are a waste of time and effort.The last caplock I made was copied from the Peterson Hawken shown in Bob Woodfill's book and it resides with a friend here who collects my locks and triggers.This lock was like the old lock and had no fancy mechanism,no half cock and blue temper color springs.Completely functional but nothing more.
Bob Roller