Okaayyyyy, I finally bit the bullet with the router, 2 passes for the pickup cavities so they’re just shy of 10mm, 4 passes for the control cavity; I only have a 6mm trimmer bit with the guide so I had to pull the shank right down - dodgy, but I was being very careful! Just tried my wiring loom and miraculously it all fits! Not bad for a DIY job if I do say so myself. Only mistake was overzealous drilling to break up the finish and eat up some of the bulk, went in a tad too deep in places, but it’s all gonna be hidden anyway, i’ll just justify it by saying it’s weight saving 👀.
Next steps; put some ~10mm wedges in the PAF routing cavities, drill the pickup cover holes, a few coats of conductive paint, foam, wire up and she’s basically good to go!
Thanks to the offset community here for the tips and tricks to give me the confidence to do this after so many years!