I have a bunch of paperwork with this car. The story is that it was bought in Sylacauga AL from the original owner around 1991 by a guy named John Holleman from Montgomery AL. John told me the car had only 30,000 miles on it and was a rust free car. He sold it to Wayne Smith of Vintage Autos in Montgomery. Wayne did the engine swap from a 6 cylinder along with paint and interior in 1992-1993. The car has been driven less than 1,000 miles since then. It has the correct 997 270hp heads, solid lifter cam, dual quad intake and carter carbs along with an original bat wing oil bath air cleaner. The underside is painted red oxide. It appears to have been a frame off restoration but not a nut and bolt perfection job. The paint is still holding up well for an almost 25 year old single stage lacquer job. It does have the original 3 on the tree manual transmission and stock open rearend. It should have a rubber mat rather than carpet. I don't know of a 150 ever having a horn ring so that may not be correct.
I added some images as requested. The car has the original ball joints that are still in good working order. Those are riveted in from the factory. The control arm bushings are totally dried out so we replaced those with original style rubber bushings and added new front shocks today. We also added new idler arm bushings top and bottom. One shock had "56" on it so maybe it was an original. It is unusual for the entire car to have been rebuilt with no change of the front end components.