it's not as complicated as it looks. it's just disorganized
you can get the buffer/preamp breakout board pre made here... http://www.wald-electronics.com/wald-electronics_shop/tiger_preamp_clone.html
then you have 2 pickup splitters, very common, just a shunt for the series link. a strat 5-way switch, and individual tone controls. the neck and bridge tone control are a stacked(non concentric) pot so they are wired just like individual tones, then the only weird thing is the effects loop that makes use of a stereo cable that gets injected after the buffer and before the volume.