Rather than produce complete turn-key cars, doing the replica body cars, using everything completely new, it still might be better to use existing available parts to re-build hulls with a factory VIN than not. I recall there being a limit of the total production which is well under 5K/year. NONE of this will be inexpensive, by observation.
In the realm of factory restoration parts, as a point of reference, any approved supplier that wants the "Restoration Parts" term attached to their items, first will need to supply finished items built to the original OEM specs for approval from the OEM, which will sell them exclusively with that notation. Once that is all approved and such, then the supplier will pay a set fee (used to be 5%) for each item sold in order to use the "Restoration Parts" logo.
When Chrysler got into the restoration parts realm of things, their operatives claimed that they pulled the orig blueprints and then went back to the people that built them back then. As it turned out, FEW of the older people at the vendors were still around. Additionally, the parts under the "Restoration Parts" flag were the last-design-build versions. Which means that a 1970 electronic voltage regulator, which was "service replaced" with a factory unit would be the 1972 version of that regulator, for example. So it's not completely accurate, but still a factory -spec part. BTAIM
In the current time, it still might be best to see what AMD has in their catalog for that "parts car" to rebuild it.
Just some thoughts and observations,
CBODY67