I wanted to report back because I appreciate those here who took their time to provide answers to my question. Today being yet ANOTHER rainy day in Berks County PA, I decided to dig into this project.
While I really appreciate Jim Kibler's very kind offer to do this for me, I wanted to try it myself. Knowing that I could buy interchangable replacement parts if I messed-up gave me confidence. Bottom line - it was easy-peasy to do, didn't take much time; and I ended-up with a crisp, slightly sub-2 pound trigger pull with zero creep or overtravel. Bashing things around a good bit to try jar the sear out of engagement with the cock at full bend, had no effect, so I feel the work did not compromise safely at all.
First, I carefully stoned the sear notch and the sear nose - not changing any angles, basically just mirror polishing with a very fine stone under magnification.
Then, I thinned the sear spring. I didn't want to use even a small grinder, like a Dremel, for fear to going too far, too fast with that already rather thin metal; and/or introducing any heat and screwing-up the temper. So, I just used a fine file and my engraving vise. I went very carefully, frequently going through the tedious process of reassembling the lock to test the strength of the spring. I filed the flat and a slight bevel on each side.
Eventually, I got it thin enough for the pull weight I wanted; then finished and polished the spring, so that hopefully no cracks could develop along the file stroke marks. This is the best pic I could get of the completed file work to try to show the final thickness of the spring. It's not a very good photo - sorry.
I didn't need to do anything to the mainspring.
All back together with a perfect rigger pull. Thanks again to those who helped and to Jim Kibler.
Greg
A note on Kilber sear springs, you want the spring to work on its entire length from the sear pivot screw to the back end of the spring, so be careful as to not shorten it. they’re a little thicker in the back end, so if you shorten the spring away from the sear pivot, the bottom leg will be doing extra work, you’ll up with a trigger that is extremely difficult to pull. Work in the bevels to lighten, they’re purely decorative but also can serve a purpose to lighten the spring.
Also be mindful of your work holding, a small bend or too much pressure can ruin a sear springs.
