I'm still a bit confused. Would it be an option to keep the 1 toggle configuration like it is now (but wired properly of course :-)
If I wire the mid PU together with the neck PU to the toggle, Can I turn down the volume of one of the PU's to have the other on?
toggle up: neck + mid (so with either volume down: mid solo or neck solo)
toggle mid: neck + mid + bridge (with volume altering: all combinations possible)
toggle down: brigde only

I'm sorry I don't understand more of it. I hope to be soldering pretty soon, but might need a guiding hand until then.
Thanks so much