
So, I ended up purchasing new pickups for it. I ordered a Dimarzio Super Distortion for the bridge and a Super-2 for the neck. I plan on adding coil split switches. Since the new pickups have not arrived yet and the stock ones have 4 conductor wiring, I will start by adding the coil split switches and I’ll add the new pickups later after I get them delivered here.
Thankfully the body already has routing for traditional Jaguar wiring, as you can see from this photo I found on the webz of someone else’s guitar:

So my plan is to drill two holes on the pickguard in the place above the body route where the 3 slider switch plate goes on a traditional jag. There I will place mini toggle switches to coil tap the hambackers.
Wiring the switches for coil tapping seems pretty straightforward:

However, having zero knowledge of how electronics actually function, I have a question about how to wire the ground on the mini toggle switches (SPDT on/on). Do I have to solder the ground to the metal body of the switch as well as to lug 3? I’ve encountered some switches on other guitars where this was the case but I don’t actually know why or if it’s needed in this case. I’ve found several coil tapping wiring diagrams on the webz and none of them seem to indicate that I need to do this, but I figured it’d ask before I potentially mess things up.