Interesting...as I have been thinking of performance a similar mod to a 'hog M65 that had a neck repair!
Only difference is I would use a Guildsby.
The attached picture is what gave me the inspiration.
M
A few other Guild triple pickup models...
The Starfire 4 is from the defunk Nashville Custom shop. It has 3 Volume and a Master tone control. I prefer this wiring configuration because it covers all options. The little switch is 3-way. Up the large selector switch functions normally,small toggle in middle position adds the center pickup, small toggle down selects center pickup only.
The modified SF1SC has the 6-position switch. I changed the stock pickup selector knob to a "chicken head" knob to make it easy to grip and indicate position. The pickups are DeA 2k's I had hanging around. Easy swap. Only the bridge position pup had short wires making the splice a little tight.