Yep, I am well aware of the SVRA rules. SVRA has two different classes for these cars depending on how closely they are built to the original period car, the first class is Group 6 B/P and the next class for a car built to original period specifications is Group 6 B/P Gold Medallion.
Standard Group 6 B/P rules:
http://www.svra.com/wp-content/uploa..._Group_6_a.pdf
The above program allows any manufacturers reproduction to race as long as these rules are adhered to.
Group 6 B/P Gold Medallion rules:
The SVRA Gold Medallion Program | SVRA
So, I am assuming that given the depth of "originality" that is being put into the alloy bodied cars that they should qualify for the "Gold Medallion" program?
There has been numerous speculation that some owners of extremely rare and valuable original cars have commissioned copies of the original car so that they can race it under the guise of their original for obvious reasons.