Share 'Complex (?) wiring struggle'

Hi guys, Iv wrangled with this on my own for far too long now, so Im hoping one of you wiring genii can solve it! Im building a guitar for a chap (its a hybrid 4 string SG type thing) - he has provided me with 3 high output humbuckers (Seymour Duncan, Dimarzio etc), and a triple shot ring. The 3 pups are to be wired each to their own on / off switch, and all through a single master volume pot. No…