Hey Rob, finally getting around to it are you, I had a strat p/u solid mounted in my tele but without a pickguard and I recently swapped it out for a SD Hot Tele, and I also finally put a pickguard on too, I did not solid mount the p/u, I chose to use the modern style pickguard with the adjustment screws, seems to me you have 2 options, use the modern style pickguard or once you have all your parts, set the neck p/u down in the cavity ( they do fit fairly snug and don't have much wiggle room ) then carefully set the pickguard down over it, make sure everything is setting right, then carefully lift the pickguard back off, take some small thin pins or nails, (brads) and push them thru the mounting holes in the p/u into the wood , then place the pickguard back over the p/u and check the fit, if all is well, then you can drill for the mounting screws, just a word of advice, when using multiple suppliers you may run into some issues with how things fit/ match up, make sure you check all possibilities before drilling holes etc,, Good Luck with it.......