Here's my latest find from ebay. It's a 1976 Rickenbacker 3001. Electronic-wise, it's identical to a G&L L series bass, except for the active preamp. A hot single coil pickup, volume, and passive treble and bass cut controls. Sounds like a P-bass on steroids, and quite similar to my L2500 in passive and with neck pickup soloed.
Looks like it's not Leo who first came out with the idea...