Mainsprings are 2.250" long, 0.270 OD, wire diameter was 0.064, looks to be 21 full coils.
Mainspring Cap
0.885 OAL, front sear engagement tip is 0.323-0.325 long, 0.250 diameter, the sear edge might be 0.064 thick. The outer part of the cap most likely has few really critical dimensions. My SWAG is the sear edge width [0.064] is one.
Cap stem [slides inside of mainspring] is 0.157 diameter, 0.560 long. Stem diameter is limited by mainspring ID. Length could be off a little and it wouldn't matter much.
The cap tip has two milled surfaces, one is a straight surface [on the downward side], the other is curved [on the upper side]. The curved surface is probably to mate with the hammer [CPT Obvious here...]
