400 V8. http://www.ebay.com/itm/1975-Chevrolet-Chevelle-Laguna-S-3-/221791040754?_trksid=p2054897.l4275
Looks to be in great shape and well-optioned. His starting bid price of $7.500 with no reserve seems fair.
I had a '75 350 Laguna S3 in 1988. It was white with red halo top and interior. Paid $300 for it. It had maybe 75K miles on it at that time. I love the GM "Colonnade" styling.
While I agree that it is a Nice original car that is seldom seen, The roof and 1/4 rust put it out of the "nice condition" range for me.
I sure couldn't see this in the pictures posted. I wouldn't touch the car considering the condition of the top corner and the space at the windshield trim.
If done right, a body shop can replace the roof. Expensive as Hell, though. Ask this mechanic how he knows.
But...... Seeing how big the hole is I'd imagine the floor, headliner, and other things are also shot. Why buy a rusted car when there are still nice ones for near the same price?