Whew.... when you said something about the threads, I almost yelled, "NOOOOOOO!!!"
Sounds like you got it. That screw is what holds the yoke in the frame, so a "little" contact is OK.
End shake might be a little more difficult... do you have a gunsmithing background? I have no problem messing with some things, but there's a whole lot more that's better off getting fixed by the experts. I really suggest getting it evaluated at a minimum to see if it's within specifications.
Good luck!