I used one of these for a few years...factory portabilized Yamaha Electone C-605...
Pretty rare instrument as well, from what I hear...I special ordered it when I was still gigging using the organ...still needed a van, as the two powered speakers (remember the Yammie's with the white speaker cones)were nearly as bulky as two Leslies.
Wasn't near as heavy as the B-3, but I'm glad to be using an arranger today.
Only 400 lbs lighter than the B-3.

Ian