Thanks, Troy. I remember when that car was for sale on ebay. I was intrigued by the Bill Thomas sticker on the windshield. I found out that the car was built in the early '70s by a guy from the Buellton, CA area named Sig Hansen and he competed with it in A/Sedan races. No Trans-Am activity. Speaking with Sig, he told me he had purchased some parts through Bill Thomas and they came with a decal which he put on the windshield. The car itself was not prepared by Bill Thomas Race Cars. This car was sold to Jay Parsons up in the San Luis Obispo area and later went to Tom McIntyre who raced it for a number of years before he purchased Mark Donohue's '68 Sunoco Camaro. Anyway, bottomline is this red #47 car is not Andy Porterfield's old car but I do appreciate you bringing it up as a possibility.
Below is a photo of Sig Hansen's Camaro as first road raced.