got the 20 lb wolf spring and new fire pin spring and installed. I really hope it throws brass shorter. I test drove the gun before spring with 180 grn buff bore sup to be around 1300fps, but did not chrono it. Brass went a third world country far :)
recoil was less by far than my sp101 357 3 inch so not feel it at all. also got the die set and a second mag to go with the brass I got in.
I am going to polish the trigger group soon and order a few mag extensions as the standard mags are a bit of a pain.
next, need to find a mag case for belt when cc
The other things you may consider are a heavier mainspring and a flat bottom firing pin stop. Not sure what you wanted to accomplish by the firing pin spring.
pin comes in set and recc you swap out when you replace spring. Mostly for high use if wearing out springs from use, but did it as had part. Read same about main and pin stop.