That has got to be the worlds smallest truss rod cover.

Everything looks so sweet on that rich maroon carpet.  Not sure if the owner is still looking to sell, but I suspect someone will offer him a fair $3000-3500 for a functional '78 Series I without the power supply and cable.  Other than the finish on the back looking a bit chewed, this bass appears to be in pretty solid shape.  
 
Is that some sort of rosewood-family sustain block under there, or maybe mac ebony?
 
-bob

- I was just getting ready to post about the block.
 
You can see the bridge block much better in these pictures.  As Kris noted above, it does appear to be Ebony.

The bridge block is brass. There's an inlay around the bridge block in what appears to be Macassar Ebony. Here's shot to show it:

 
That is a teeny truss rod cover, I agree!

Interesting.  Thanks Mica!

Fascinating discussion, but I wouldn't spend a nickel on it unless Susan and Mica saw it in person and vouched for it.  But Mica seems to have done just that.  And I ain't gonna contradict the Alembic Goddess, no how, no way, no where.  Now I just want it!