The screw thread sizes on the action, cocking lever, striker and sear is 4M.08. I found out after a long search so I thought I would pass it on if someone need to replace/re-thread one. I did find taps on Enco but no dies so I made one for my project as I only need re-place two screws.
I have three shotguns two J P Sauer and one Simpson and all the screws are the same thread on those parts. Of course yours may be different but its a good place to start ifen you need one.