Great eyes, Dave! I wonder if you are right about the pickup selection. Only way to find out is to try it.
Pegleg, I would suggest getting the exact serial number and calling Alembic to see if they have anything on file. They can probably tell you how the bass was originally shipped, and whether or not it ever needed repair.
Hopefully those pickups are all real Alembic ones. (I have no idea if anyone else made soapbar style the right size.) The screws that hold the pickups are different from other basses you may have seen. Instead of using springs underneath for the up/down adjustment, Alembic uses two screws on top and two underneath. You have to loosen the top ones, and then slip the screwdriver down into the other two holes to adjust the height, then retighten the top ones to snug them down against the underside screw heads. In this bass, I can see the neck pickup has mismatched screws and the position is reversed compared to the other ones.
The chiseling in the cavity doesn't look too bad.
I'd also see if you can knock $100 or more off the asking price, because it is modified. It can never truly be brought back to stock condition...
The good news is, the rest of it is STILL an Alembic, so if you do get it, you will enjoy the Alembic hardware adjustments and the feel of the neck.
I wonder if it is medium scale, 32? (Measure from the nut to the 12th fret and then double the number.) A lot of people find that much more comfortable than normal 34 scale and the sound doesn't seem to suffer at all.
Good luck, Pegleg - keep investigating.
EffClef