Challenging challenger

You're going to have to provide a whole lot more information if you expect to get any useful help. Pictures might be the easiest way. At least give us the information on the ignition box you think is wired in. May not be an ignition box at all.

The brake booster is probably connected to a vacuum canister. This is probably because the cam is too large to make enough vacuum to power the brakes, at least at idle. So a canister was added to provide vacuum. But again, without pictures or a better description we're shooting in the dark.