Hi Scott,
Congrats for your luck.
The bass is very interested.
1: The article
The bass is found on the album Fleetwood Mac 25 years.
2: The neck
This Fender type Graphite neck is well known as replacement parts. But these are bolt on type.
The bass is bolt on or through neck to body construction ?
The back shot is good information about it.
3: The bridge
It has wider bridge spacing just like Fender's.
The neck was chosen for spacing, that I think.
4: The tail piece
The tail piece shape is unusual !
What's shape, it is !
5: The top wood
The photo shows Very dark colour and straight grains. Is it Rosewood or Ebony sp. ?
( I think, the bass has Ebony top when I saw the album.)
6: The controls
These knobs are Super Filters as 75-241.
But it has some more knob and SWs.
I have NO WORDS !
Please show us more photos with details.
I'm interested S/N info.
Eiji