I think the reason is quite simple -- the seller is an estate sale professional and in my years of going to estate sales, I will make a couple of sweeping generalizations:
a) they usually know a lot about a few things they sell, and virtually nothing about most things
b) they usually know nothing about the subtle distinctions between cars (I once saw a but-ugly RR Corniche Coupe that the guy was trying to get a convertible price for)
c) selling to a dealer usually involves either a commission or a sale for less than retail, either of which involves the free surrender or cash. I don't blame the guy for trying to sell it himself.

By the way, can you really tell what engine a car has by the shape of the grill? If the car was in a front-end accident, couldn't the shop have put the wrong grill on? Just curious...

Catrinus
73 280C