And another one bites the dust...
The Kahler does look to be the correct model for a mid-80s G&L, but the locking nut monstrosity is definitely not original. Here is what the originals look like:
Another clue that the hacked-up ASAT on eBay left the factory with the Kahler is the lack of a boxed string retainer on the headstock. Contrast the headstock photo above with this one, which is a hard tail ASAT (both were from May/June 1986):
Notice that the Kahler-equipped ASAT has a recessed truss rod nut, while the hard tail has the bullet typical of mid-'80s G&Ls.
I think the guitar on eBay has been refinished rather than just sanded down to a matte look. One clue as Ed pointed out is the black paint on top of the drilling marks in the pickup cavity, but also there are no visible traces of the mounting screw holes for the pickguard. They must have been filled before the refin.
This one could be restored pretty easily. A single-ply black pickguard would cover the enlarged pickup cavities, and the finish could possibly be buffed to a respectable G&L black. If my ASAT quota wasn't full, I would think about bidding on this one as another rescue project.
Ken