It's worth about $50, and is going to sound absolutely terrible. I'll do you a favour and take it off your hands if you like.
Srsly- beautiful looking guitar.
It should be quite easy to figure out a wiring diagram. It would just be each pickup into an on/off switch, then a combined Vol/Tone circuit. Not sure about the other switch- possibly a tone circuit or a phase reversal?
In the absence of a proper diagram I don't think it would hurt to leave that disconnected.
RE: Screw holes on the scratchplate...I wouldn't sweat 'em. When I've encountered loose holes like that I just fill them with a little bit of matchstick. Don't even need to glue them down.
RE: Tuners- you will be able to get something that will fit the holes that are originally there and look close enough, and probably work better than the originals.
RE: Bridge- you could just get a nice new tuneomatic to stick on there. Otherwise you could get something like the original from stewmac...filed under 'budget bridges'