Back in the late '70s a lot of players in the really hot Indianapolis bands (Light, Roadmaster, Henry Lee Summer, etc.) that came through my area had either Alembic or Modulus basses and Bag End cabinets. Even though I was only in high school at the time, J.T. Corenflos and I could usually get into bars when these guys were doing their sound checks because they all knew him (he was like 14 at the time), and I almost always got to touch and play their basses. The necks on those early basses were so small I couldn't imagine where there was room for a truss rod!
I don't think I was aware so much of the Dead connection as I was Tom Fowler and whoever it was that played for Manfred Mann at the time, who I think I saw on TV with one, and of course Stanley, then JAE. I finally made the pilgrimage to Vic's and was blown away by what that (insert interesting adjective here) guy had in stock. Dozens of Alembics, Turners, Modulus (at one point the 18-string monster bass that I actually almost bought), and everybody who worked there knew their stuff inside and out. He was more than happy to have a 17-year-old kid from the sticks spend as much time as he liked playing and drooling over whatever he had in stock, and the other musicians who would come in would always let anybody play their instruments and we were all ever so careful with them. It was a different world back then...
I played in a band with a guitarist who had an Electrum for awhile. It was during that decade where everybody used chorus on everything, so I have no idea how it sounded.
Ironically, when I lived in L.A. and Nashville the only people who knew what an Alembic bass was were the smiling engineers.
John