So, I want to build a tester guitar for pickups... i'm thinking of just making a cheesy bolt on out of a block of poplar, a tone knob and a volume control and a cavity routed through the back of the guitar so I can swap pickups without having to remove the strings with locations for neck bridge and middle positions...

any pickup builders have anything like this? or maybe some other type of test rig? I'm only going to contemplate this if i can get a real dirt cheap neck and parts... otherwise I may just molest the crap out of a 100 dollar clunker...
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Timpson Guitars and TDM Pickups rock ;D

I make guitars and pickups. I also make sh*t that'll blow you the f*k up as well as things that will rebuild you - I have the technology
I had the same idea and it sounds like it would work out fine, though I have yet to get around to making it and pickups.
Main gear
Shine ST420F
Epiphone 1966 Limited Edition G-400
Martin DX1K
1976 Silverface Champ
Egnater Tweaker 112 combo