Just found this thread. Back in the early 70s I added a second mudbucker in the bridge position to an EB-0. A three-way pickup selector switch, second set of volume and tone pots, and an in-phase/out-of-phase switch were added. It made for an interesting tone variety, especially the out-of-phase position. Unfortunately, it still could not produce the highs that became popular in rock music at that time. I purchased a Fender Jazz bass and sold the Gibson, as I could not afford to keep two basses. I would buy that bass back if it ever showed up for sale.
