Dave - sorry to hear that! I've done it myself - what it it with basses?! Mine was a Jazz bass - luckily not too much damage and only about a 3.25mm hole.

Where the pre drilled hole is a bit small, I've taken to enlarging it a touch, but have learnt the hard way to do it by hand - without a drill at all - too easy for it to keep going out the back...

BTW - have you thought of changing to a black pickguard?