Seth, welcome to our hangout.
I think you've identified a couple red flags, but they aren't necessarily prohibitive of a deal. If you can get some assurance that the truss rods (there are 2 of them in that bass) are operable, (and they probably are fine) and get some satisfactory information on the weight, then you might be able to deal.
I would suggest emailing Mica about the cost of replacing the pickup, as that would be a worst-case scenario. Personally, I think it's fixable... I have repaired the broken 'ear' of an AXY pickup with Devcon epoxy. Mixed with a little black filler and it's a very good hide. That being said, Mica can set you up with exactly what you need right outta' the box, and you can sell your originals to defray costs.
Yeah, I'm with the fellas here. That bass is an $1800 - $2000 fixer-upper. (my favorite kind!) I think the seller just looked around at what others were pricing Distillates at and went just under it because his is rough.
FWIW, I bought a mint-condition Custom fretless Distillate for $200 more 2 years ago. Virtually unplayed 1985, still had wax paper on the brass parts and original hardshell case. I paid considerably less for a 1981 Distillate in VG+ condition a couple years before that.
Good Luck, and again, Welcome.