I was reading the description of a new Further posted on Reverb by Miami Vintage Guitars, (it's a really pretty one), and the listing included this quote from "Alembic History, The Long Story", posted on the Alembic website:
During 1969 we developed the Alembic electronics and pickups. We first installed them in David Crosby's 12-string Guild guitar (which he still uses to this day) and then into Phil Lesh's SG bass that had been hand painted by Bob Thomas in his trademark renaissance/psychedelic style.
I believe Crosby's 12 string, (which I had the fortune to play a few years ago when it was back at the Mothership for a tune-up), is actually a rare Gibson Crest rather than a Guild. The Crest was similar to a 330 with a Brazilian Rosewood veneer. About 172 were built between 1969-1972.
Bill, tgo