Paul: The AC428 with body by Frua debuted as a convertible prototype at the 1965 London Motor Show and as a fastback GT at Geneva in 1966. Production started in 1967.It was based on the 427 coil spring chassis, lengthened six inches, with softer suspension settings. AC built 58 coupes and 28 convertibles before production ended in 1973. It appears its lack of success was attributable to "bad timing" with the first "
oil crisis" ruining the demand for seven liter cars. My two cents....