We haven't heard from Jimmy in a while, so I'll answer based on conversations I've had with him.
The original Bass of Doom was Jaco's old Fender. Also, Jimmy had a habit of using doom to refer to things that are awesome. This bass is newer than mine (June 2000 for mine). Jimmy and I talked on the phone about my bass as he was deciding what he wanted on this one. It's probably a 2001. It was his 2nd Alembic at that time.
Peace,
James
(Jimmy - if you're lurking, pop in!)