Maybe a liquid paint stripper, like sold at hardware stores, could take enough of the top layer of paint off of Fender/ door sides to see if any writing or clues to it's past. Also, the Yenko site has some knowledgeable guys that have a lot of old racing pics and know a lot about different racing car's histories.
Any car like yours I like because it is obvious of some drag history and think it's neat just 'cause it is not messed with. Back when I bought my cars I shied away from the ones that were butchered up, looking for cars with OEM parts and not cut up. In reality, I probably passed on a COPO or Z or something not knowing what it was BITD just 'cause it looked like your car, meaning looked to have had been raced seriously. Today, I would love finding a car like yours as it is intriguing and I like period correct mods. It would be nice to find out the story on what happened, like when it was raced and why was it "put out to dry" until you got it.