A long time since I did my .22 Model 50 but I fitted what I think was Chambers recommended spring and it turned out rather harsh. Needed shortening a turn I think.
Leather cup washers/seals, if dry can come back to life if soaked in thin oil (no chance of dieseling a model 50). As they are a sort of parachute seal, they self adjust if flexible enough so wear is less of an issue than with some seals. Nothing wrong with leather cup washers if in good enough condition. Home made ones are viable if needed I think.
If you have not got that far, the trigger balls are fun to assemble but easy if you blob them in using grease. I made a spring compressor for re-assembling my gun, m12 stud bar with a small metal end and a wood chassis. Re-assembly without seemed risky.
If you are happy with about 6 1/2 ft/lb then they can shoot really nicely. I got mine to 8 and thought it too harsh so I shortened the spring.