Hello.

It would be virtually impossible to even ballpark it without a lot of detailed pictures and some information on the car. A Marti report would help a lot. As goofy as the market is lately, it's hard to say even with all of that.

However, I have trouble thinking that, if the car is solid, basically rust free, not all hacked up or restomoded, runs and drives like it should, brakes are good, no electrical weirdness going on, interior is ok, that it would bring less than about 20K if it's originally a 6cyl car, a little more than that if it's a 'C' or 'A' code car, still more if it's an 'S' code and quite a bit more for a 'K' code. They only built a couple hundred 67 K code fastbacks.