Degrease and use "Guntite" which is a Loctite type product, (might be from Locktite, I don't remember). I've got a little tube somewhere, had it for years, still not used up.
It holds screws well, and they come out normally using a screwdriver.
I don't remember does the Ballester Molina use grip screw bushings, or are screw holes directly in the frame?
The entire point of the 1911 using bushings was that, if you were going to bugger something up, you (usually) buggered up the bushing not the frame.
Loctite makes a range of products, some of them are PERMANENT, be sure to use the correct one for your purposes.