so, erm the o6 frame has the inbuilt rail at the bottom of it, it also has two holes drilled into the bottom for a rail, if i were to sand off the inbuilt rail are the holes threaded to take the o5 micro drop?
You dont really need to file it off, get longer screws. Might look bit crap but no one will notice and if you ever want to sell it, it wont affect the re-sale value. Just chuck the old one back on.
Nige