the diagram for the switch he is using is what throws me, it has a common, the base of the arrow, and 2 poles, the positions the arrow can point to. As it is wired now, in current switch only the bridge will operate, the neck is a loop that gets bypassed (electricity seeks the shortest path) and thrown the other way the Neck operates.
A 3 "POLE" switch is what he is tryng to represent? well then he needs a common for the out put, which he has not there. A 3 pole would have 4 points, common, 1, 2, 3, . One thing you have to remember, a 3 pole switch has no off, only single pole single throw switches have off, the rest only redirect the current, a single pole single throw ids off or on, a 3 pole is 1, 2 or 3, something is always on.
So if that is the diagram, we need to know which pole is common, and add another pole, so we can straiten out the wiring, plus, we use 2 pole switches not single poles for 2 pickups