So, when faced with the fact my pillar drill to won't be able to widen the holes for the nice two point tremolo I've bought I just went out and bought a more traditional six screw one.
It's not quite as nicely made as the two point one, which really is lovely but it does just fit straight on. I can always go back and fit the two point one later.
My next move is to route out a space for the battery box and I've waved it vaguely at the guitar body this evening. I'm not really happy with any of the candidate locations, I'll have to tape the body and start marking it up.