This is all very helpful. I noticed that when mounting the Dimarzio pickup the pickguard was notched for the corner of the pickup. But I imagine a pickguard would be the easiest and least expensive item to replace.
Random musings........
I think it's pretty clear that the future of this bass is as a player, not as a collector piece. I don't really know that I'd want to put a mudbucker back into it, as I probably want a bit more clarity...and a period pickup would be fairly expensive. The BadAss bridge has probably left a footprint from being there - aside from the screw holes - but a Hipshot SuperTone replacement for the 2-point bridge would look better to me. I doubt it would cover the screw holes.
This weekend I'll pull the plate off the back and try cleaning up the jack contacts - there's a chance it might yield a signal instead of hum. I can hear notes behind the hum, but it's a hum-to-signal ratio of about 9:1. Pulling the back plate will also give me a look at the electronics - no telling what kind of hack job was done there. If that's all messed up, I can call the owner and see if he minds my coming up with a workable connection to at least make it playable. Since the original wiring has been hacked, I can't see that moving a few wires and creating new solder joints is a "value" issue - and after all, it's destined to be either a player or, if he keeps, it, a wall-hanger.
The good news is that if the top market value is in the $500 range, that might make it more practical for me to take a shot at it. I am a bit of a sucker for the EB-0 and SG-series...and I strongly suspect that the bass can be acquired at less than market price. However, I do not intend to do any lowballing to my friends - if I tell them I'd like to have it, I'll give them the best info I have about market and practical values, and let them take it from there.
I have that pair of T-bird pickups I planned to put in an Epi EB-0...but I haven't done any routing on the Epi. I held one of the T-bird pickups up next to the open hole for the neck pickup...the body of the pickup would fit but the mounting ears/tabs would require a slight hole enlargement on each side. Custom trim rings would be needed to cover the open rout space at top and bottom, since the T-bird pickup is not as square as the original. (I frankly think that Dimarzio is one uuuuugly pickup, and if I keep it, that pickup leaves.) I know that having a '64 EB-0 with a pair of modern T-bird pickups might be heresy, but it would be less esthetically offensive than what's in there now. Any comments about whether T-bird pickups would be a good or bad idea?