Re: floyd rose in a Jackson licensed cavity?
What he said. ^
I can't imagine how a file would do. It's just two holes, but they had better be in the correct place, shape, depth, and at the right angle. I'd look around a bit and see if I can find a woodworking or machine shop nearby, equipped with the right tool and ask if I could use it for the task. It's a 10 minute job at most, but can end up in an ugly accident if you're careless. I'd much rather just use existing anchors with Ping studs, than risk damaging a decent body.
As far as I know, R3 and R4, are both 42.8 mm wide, but differ in string spacing. The narrow spaced R3 is recommended for bound necks, the wider spaced R4 for necks without binding. An R3 would work just fine as well, if you wanted a little extra margin around the outer strings.