Alternatively you might be able to take the part to an engineering workshop and have the stripped thread re- tapped to match bigger screws.
I think the locking device just keeps it in tune, should you accidentaly knock the machine heads, and should play without it ok.
Good Luck
if you always take the lazy route
The Devil knows your every move ![COLOR=RoyalBlue]
The Devil knows your every move ![COLOR=RoyalBlue]