A bit more progress on the PRS today. I traced the control cavity on the back of the guitar and cut a cover out of a pickguard blank for it. Successive trimming on the bench sander allowed me to get a reasonable fit. Not perfect, but not bad. It's very hard without the original routing template to go by (at least that's my excuse)!
I also got the headstock sprayed black and a couple of layers of Minwax Wipe-on Poly applied. It's not my best headstock attempt, but it will do in a pinch. I really should have sprayed it *before* applying the Wudtone to the neck (like I did for the Stone Roses Tribute) but I did the best I could under the circumstances. Lesson learned for next time > do all your staining and spraying before touching any Tru-oil or Wudtone!