Pavulon, you may be a "glass half empty" guy and I may be a "glass half full" guy. If you have ever changed a fanbelt or removed the fan/alternator assembly, you know how tight a workspace it is. An emergency roadside repair of a fanbelt using the factory tool kit has a high probability of busted knuckles and "wrench rash" to the painted surfaces under the deck lid.
If the car presents an overall condition consistent with the odometer mileage, then I wouldn't be overly concerned that wrench scratches under the deck lid are indicative of some serious deficiency in maintenance. Maybe a less experienced or DIY mechanic...ok. Or maybe some emergency service required by non p-car specialists. In either case, for a 29k mile car, the repair work is likely limited to fairly non-invasive surgery. For a 29k car of this age, I'd expect that the alternator may have been replaced, intercooler seals, fan belt, spark plugs, cap and rotor. It's when there has been head work, cylinder head studs replaced (I believe this car came with Dilavar studs, so this should be checked), engine case split, etc. that you need to really worry about who did the work.
And guess what? Even if a celebrated p car mechanic who is regularly mentioned in Excellence magazine did the work, you may still wind up with an expensive basket case on your hands. Such is life in dealing with 30 year old cars. Anyone who isn't prepared to accept this possibility should head to the dealer and buy a brand new car with a warranty.
As to the question of value of this car, that is of course highly subjective. It looks pretty nice overall, but photos can hide many flaws. I'd need to evaluate in person for that kind of money. I don't see myself ever shopping in this end of the market anyway. I've tasted the fruit of the modified 930 and would rather buy a modded car for less money that can be driven without guilt. For the right buyer, looking for a specific color/year, etc., this car may be just what the doctor ordered. Probably was a doctor who ordered the car originally In 1978
. I bet you could negotiate with Sloan to repaint the scratched areas under the deck lid.
In any case, different strokes for different folks, YMMV, Caveat Emptor. Enjoy the ride.