By far the simplest will be a pickguard. It can be whatever shape and size you think fit, and colour and material will be choices too. The damaged area looks pretty flat, but if the pickguard needed to go close to the edge, it could have a spacer under it at the point it gets screwed onto the body.
The existing holes could then be opened up to allow the body of the pots and switch to fit easily, all of which I guess is accesible from the back. You could even move the switch and pots if needed, with any extra holes made then covered by the pickguard.
At the same time, maybe consider some alterations to the controls - phase switching, tandem pots, etc. With those pups there will be many options, and another switch or pot won't go amiss, surely?
Consider either leaving the damage, or filling it in - there may be some gain to the tone one way or the other - albeit minimal.
To keep it as original as possible, John's idea of washers is the best - maybe carefully routing out enough depth for them - otherwise you'll end up painting at least the top of the guitar.