A while back there was a thread on Tom Petersson's 8-string Alembic, but I came across some videos from 1978 on YouTube!
 
auf wiedersehen  
 
surrender
 
There are more videos than this, but these have some good views of the 8-string.  
 
Here are a couple of stills:
 


 
 


 
 
I did the second one to confirm the knobby headstock.
 
This makes me want an Alembic 8-string even more!

Some superb footage of cheap trick in 1978 featuring Tom's 8 string. Sounds like thunder..
here
 
graeme

Someone on Facebook posted this pic of Cheap Trick (pre-Live at Budokan?) - they were posting for Robin Zander's Rickenbacker guitar, but of course I immediately noticed the 8-string Alembic! Same as in the shots and video above?