Buying this car would be like having sex with prostitute without a rubber, and washing off your penis after the deed is done...just in case. In other words, for those who are a bit thick, this car presents a HUGE risk.
It sounds like there's nothing at all to pacify the buyer into thinking this car had all of the important bits like belts, rollers, cam chain/pads, water pump, clutch, and power steering gear serviced. It'd be Russian roulette just starting the thing.
The seller mentions that more cabs than coupes were made, when in fact it's the other way around. The latest figure seems to be a total of 12,776 units made with only 4,389 cabs total deducted from that number. That leaves us with 8,387 coupes of which 2417 became US/Canadian citizens compared to the topless versions at a close-but-no-cigar 2,248.
I'd set aside maybe $4-5,000 to make it confidence inspiring and still come close to market value in the end...all in. And the price is never firm. The last time I bought a Porsche with a "firm price" placard affixed around the seller's neck, I coaxed him down $950 more.
Just trailer the damn thing home. Drive it and consider yourself lucky if you just end up with crabs when you arrive.