There are two extra switches, but the control layout is not a standard Elan Plus layout. It looks like a standard Elan layout with the extra switches added. Perhaps the owner had it upgraded to Elan Plus; or perhaps some other modification has been made.
The knobs appear to be missing their caps. Hard to tell from the picture ... in fact, the more I look at the pictures, the more it looks like they may not be Alembic knobs. Just hard to tell from the picture what's going on with the knobs.
Custom neck taper. If I recall correctly, Elans had/have a classic neck taper, which for a six string would be 2.000 at the nut and 3.125 at the 24th fret. Europas have a comfort taper, which is 2.200 at the nut and 3.560 at the 24th. This one is 2.482 at the nut and 3.56 at the 24th.
Needs more pics.
I think anyone considering this bass should request a picture of the inside of the control cavity.