Hi fohat.digs,
Don't get me started on the supposed strength of epoxy bonds, as the strength of the bond is so very dependent on surface prep, actual materials to be bonded, proper mixing of the 2-part formula if used, proper clamping of the parts (difficult at best due to the curvature of the backplate and general construction of the M), curing time and temp, etc. etc. etc.....
My personal motto about glue -- actually just made up specially for this occasion:
"If you don't value it, glue it, otherwise just screw it!"

I think we both agree that a proper bolt-mod is vastly preferable to an epoxy mod, especially if you need to open things up again later for any reason. I've got some 52G and 82G M's and have bolt-modded a couple of each; actually they're not too bad, but I agree that the older and heavier M's are more desirable and more worthy of the effort.