Looks sort of like a round sardine can or maybe a thin tuna fish can which houses all the actual electronics. There's a company that the name escapes me right now that has made a modern solid state upgrade that's a direct fit into the "can". The cans were found in 65-66 Barracudas for sure and maybe in 67-up but not sure about that. They were also found in all 66/67 Chargers as well. I can get a pic of mine tomorrow for reference.
EDIT: BTW, no such thing as a stupid question, just The one that wasn't asked!