Other possible sources are Ken's Cougars (www.kenscougars.com) and Semo Classic Mustang (www.semomustang.com). Ken used to have a number of 428 Eliminator Cougars around. Bound to be more, but I know Ken had a few. Not cheap, but he was good to deal with from my point of view, and Jeff at Semo is a top-notch guy.