A piece of an emery file might work as well. If not, you could buy a small
pack of cut off wheels pretty cheap. Just break a small piece off the cut
off wheel and position it where the clip and pivot barrel meet, then tighten
it down snug but not to tight. It worked like a charm for me.
Another thing you can try in addition to the above is take the tip of
a soldering iron and place it on the pivot screw just long enough to get
it warm, then try backing the screw out. Try not to get it very hot, it could
heat the blade up as well. I wouldn't advise this with rubber material, you could
have a mess on your hands. Good luck and let us know how it turns out.
SV