if it was made in Wis, probablly a 76 or newer CobraJet, does it have a walk through window, the Cimirons looks pretty much the same and the wreidts are close, I have a 74 CobraJetbut the decks are a little different with a wrap around window, check out sidewinders forums, one of many splashes of the winder

Looks like an old Marlin to me....