Well, I took it to band practice last night and it worked and sounded like a charm! It mixed well with the other bass I brought (Fender Dimension H). Pretty much the same output, but the Dimension is much brighter.
Firstly WOW that looks amazing

great work it looks like a prototype that, Peavey could have made when they were designing the Foundation

. Is the mini switch series/parallel and what is the weight like now with, the T-40 pickups installed.
Thank you! If Peavey were like Fender, and they were getting rid of T parts while transitioning into the mid to late 80s era of basses, I could totally see this as one of those models. A transitional Foundation made with some leftover T parts.
The mini switch is for single/dual coil for both pickups. I tried to do the spin-a-split when I had one Toaster, but it didn't work well with the VVT controls. There would be signal bleed from the pickup in single coil mode, even when it's volume was all the way down. Perhaps spin-a-split needs the isolation of the pickup switch to work properly..? Either way, the switch works perfectly. Maybe I might do another switch so I can independently split the pickups, but chances are slim. I prefer the sound of the bass in humbucking mode and the dual split tone is nice and grindy.
I would have to take the pickup apart to wire it for series/parallel. Not wanting to take a pickup apart, because with my luck, I would ruin something!
The weight didn't shift too much. Toasters weigh about 9-10oz each, Super Ferrites about 5-6 oz each. The bass went from 9 pounds, 2 ounces with two SFs, to 9 pounds 6 ounces with one SF & one Toaster, to 9 pounds, 12 ounces with two Toasters, mini switch and Hipshot Xtender key. I guess the bass lost a
tiny bit of weight from the extra routing, maybe an ounce or two. Interestingly, it's now the same weight as my stock 84 Foundation.
@bigtone23 would you be willing to open up the SFs you took out of the bass and give us some gut shots, dimensions, anything that could be useful to getting more custom made?
You mean the Toaster? Super Ferrites are encased in epoxy and virtually impossible to open up.
Either way, no. Sorry, I'm not comfy pulling apart these pickups. I think I saw somewhere on the web where some people have taken T pickups apart.