It could make a great weekend toy but you really don't want to use a car that old as a daily driver. (I have cars that old and older.)  The mileage is obviously suspect - odometers of that era would roll over after 99,999 miles and it is likely that is what happened here, at least once. Particularly if it has a lot of original rubber parts and the car has been sitting for a long time it might well need a complete overhaul just to make it driveable. Another red flag is its being sold by a dealer.

It would be better to pick up something newer as a daily driver and find a more reasonable buy on a classic car to play around with.

Unless there is documentation to prove the mileage I wouldn't believe it. If the car hasn't been used in 40 years there could be an unimaginable number of problems. Possibly a weekend toy or project car but definitely not something to think about as a daily driver. Also see what your insurance company says about it. A standard policy is probably not in the cards.

A find like that is quite rare and I would be super skeptical. The odometer could have rolled over once or twice, engine and transmission replaced, etc. There has always been a lot of car flip scams out there. Get an expert to check it out for that much ca$h first.

Run away, not worth it.