I've been trying to track down the name of a bass for a while now.
It is in this video; Magma 1975
The bassist is Bernard Paganotti, and you get a clear shot of the headstock at 4:15. On my laptop screen it looks like it reads something with an L and a B in it, but I cannot figure it out.
If nothing else, the video shows some really good performances by Magma!