Right now, my project involves a complete teardown, breaking a lot of sharp edges internally, just so I don't rip myself up if I work inside again. Then some nanolube, and experimenting with spring rates.
In your case, a couple of teardown steps beyond basic field-stripping will expose enough of the critical components for an application of nanolube.
Then shoot a box of ammo with your present spring rates to work in the nanolube, and see how much has changed. A rule of thumb I got from the CZ Custom Shop was that brass should be ejected only about six feet. The standard 17-pound spring weight is overkill, so they suggest trying for 13 pounds with equal reliability. Their recoil springs go down to 8 pounds, but that's for target guns and target loads.
My own theory is that most European handguns are sprung for red-hot, hard-primer military rounds, or at least the ones from that era. For CZ, the spring rates assume sov block ammo. That's the way they're sold in the the USA. But a custom firing pin, .002" longer, will get the job done with a much lighter firing pin and hammer spring. Those heavy spring rates not only affect trigger pull and return, but also put larger random mechanical stresses in all the other parts, too.
Yep Interarms .... But stainless. Also looked at cylinder and slides best ppk/s effort and 11 DA and 4 single action was best trigger they can promise with reliability .... Good luck !!!
Thanks !!!