What's it Worth Unknow manufacturer of carb heatshield

[canblue]

I found this carb heat shield in a box in the back of the shed. I have no idea who the manufacturer is or the full function of it or what size carb it fits. Wondering if anyone can shed some light. I would like to sell it but I have no info on it.
Thanks.

 

[jimbosride]

GM Holley Carburetor Heat Shield 3969835 Insulator 64 - 72 CAMARO CORVETTE

Looks like someone may have done some mods to it or it's an aftermarket piece?