I.D. help please

Does anybody recognize this part ? It's a Shelby air filter cover but what's it from ? Mustang ? Cobra ?
Dimensions are 10x21

 

i didn't know folding chairs had aircleaners.....mustang and cobra's ran those. may be a repop.i dunno if they ever repoped those though.

 

I've seen them on both the mustangs and the cobras

 

If orginal to be verified by the casting number its a decent piece. They were a option, cobra dress up kit, that from a dual quad car.

 

Worth some $ it is