Info from Dr. John Craft on the B302 Forum in 2004 about his visit at HM back then..
"...the remains of the Ken Miles J Car(in which he died at Riverside), the remains of the Les Ritchie AFX Mustang... and the remains of the Fireball Roberts '64 H&M Galaxie (in which he was horribly burned at the World 600 in May 1964). When Ford cut H&M loose at the end of the '70 season (via letter dated 12/2/1970), they transfered ownership of the hulks to H&M. Per Lee Holman, the cars were ultimately cut up. "