I vowed this would never happen...

[Dmoney]

you'd need an SG style 3 way toggle. (the tall style gibson toggle won't fit... too tall!)

The tone pot on mine was a push pull pot with DPDT switch. I think mine was a 16mm Alpha. It had a narrower bushing than the CTS pots. The hole in the body for it is a little wider than the bushing on the pot. I remember the washer off that sat on the top of the body being a little deformed.

You also need a 500K volume pot (i used a 550K BKP). with a 0.022uf tone cap, and a 180pf Volume Bypass cap.

There is a diagram made by PRS for converting 5 way to 3 way switching. I think one of the pickups in the 5 way rotary switch guitars has flipped magnets or something, so it's not as straightforward as I thought to rewire while keeping the original pups..

[Philly Q]

I've seen PRS sell a drop in kit but it costs £60+. What would I need to be able to have a Volume, Tone w/Coil Split and a Toggle?

Bear in mind that you'll have to enlarge the hole for the 3-way toggle switch, so it's not a reversible mod.

(Well, it's sort of reversible, but you'd have to use a couple of big washers or something to put the rotary switch back in the hole where the toggle switch was)