I think the first one I did was putting a 69 Pontiac Bonneville roof with the vinal top on a 69 Impala. They came with that roof but most of the Impalas including the model came with the Sport Coupe roof with the curved in rear window.
I have told people that cutting down into the body on the "A" Pillar and also on the "C" pillar makes it easier to line up and it is easier to sand in the flat areas instead of sanding on the post itself.
Nice job too.
The 69 Mach I coupe brings back memories. I had a 69 Coupe that my wife wrecked. It wasn't too bad but did require new sheet metal on the front. While looking for the parts to fix it I ran accross a guy who was junking a 69 Mach I and he said I could take any parts I needed. His car had been wrecked in the front not long before that and everything was new. I took the front end with the scoop on the hood and also since both cars had black interiors I took the console, dash incerts ( both sides ) , The wheels, and the flip open gas cap.
The car was bright yellow and I did the hood with the correct simi-gloss blasck paint and also did the front and rear pans and the bottom of the sides in black. It also had a black vinal top.
Even though it was just a daily driver I got quite a few comments in parking lots that they had never seen a Mach I coupe. When I told them it was a recreation most of them said that they should have made it. I bought a new car years later and was going to put it up for sale after I fixed the brakes. One of my neighbors noticed I wasn't driving it anymore and ask about buying it. I told him I would sell it to him when I got the brakes fixed. Well by the time I got them fixed I had 3 more offers to buy the car if the one before them didn't get it. That was the easiest job of selling a car I ever had. 4 offers and I hadn't put it up for sale yet. Last I heard it was up in Indiana somewhere and still going.