Join Date: Jan 2018
Location: Coopersville, MI
If you classify the car as reconstructed I think the VIN rules become looser, but you would still be required to get the VIN verified as not stolen on both cars before you could start messing with that. In some states when you register a kit car you use the VIN from the car the majority of parts came from and it can be a PITA.
As far as sheet metal goes, I don't think the aftermarket makes all the panels for a 65 or 66 at this time. They are getting better, but just not there as the popularity of full size cars dwarf the mid size cars of the time. The collector market for a 65 Chevelle is a lot hotter than the market for a 65 Impala.
1965 and up full size Chevrolet cars are currently more a labor of love than an investment car, unless you find one with the rare top HP engine options, and then it can come down to authenticity and documentation. The earlier full size X frame cars from 1958-1964 didn't have the Midsize to deal with until the 1964 model year. They didn't even have the compacts to deal with until the 1960 Corvair and 1962 Chevy II. The C1 corvette was the only major competitor to the full size car.