Benz Refs stripped screw hole


Is there anything that can done for a cartridge with a stripped screw hole?
tzh21y
Benz has a wooden shell but the chassis is threaded aluminium.
Threads are 2.5 mm so perhaps if you try 2.6mm screws might help ?
Had the same thing with a Dynavector Karat 23R (non-standard size) that I bought used. 
I used slightly larger nylon screws - they're soft enough that they won't do more damage