Thanks for the help and explanations so far guys.
Also just ran across this related to the model and it's saying USRRC for 1966. I know the middle car existed, but would sure like to know where they got their references for the top and bottom cars... as I cannot find hyde nor hair to authenticate those two. It's supposed to be the model manufacturer's "Version A" along with their Version B and C, of which those versions do seem to match up with existing cars... so their research on these Version A cars may be accurate, but it just seems odd that there's no photos to be found on the internet anywhere.
If these cars were some flight of fancy on the part of the model manufacturer, they will usually identify as such, but I can't find any authentication in that direction either.
Sorry, my paper refs on Cobras are thin.