actually the action is very simple - the best way to make an action long lasting

I repair common airguns for friends but using only available parts you can buy. never remake a leather bucket but its not rocket science. You cut out the part, make it soft with water, then bring it in form with home made tools and let it dry.
to be true the Oskar Will airgun get a new leather bucket by my gunmaker.
I dont want to break anything on such a valuable airgun.