I am presuming you are speaking of the dovetail mount.
Remove it and put a .002 shim under it, drive it back in. Scotch tape may work, aluminum foil might also.
Brazing a thin layer on the bottom and fitting it by stoning it to fit would be an option.
You could stake it but that does leave permanent marks.
Though you don't want to, JB Weld is the simple fix, and can be removed by using a soldering pencil if needed.
I would not myself, brazing and rebluing is an answer, buying a new one may be what you need. Though buying a new part to find that the dovetail is cut too deep would be expensive.