During 1987, Kramer also commissioned guitarist Rich Excellente, designer of the "1957 Chevy Tail-fin" guitar, to create a series of guitars based on the patented features Excellente developed on his "Chevy Tail-Fin" guitar. Kramer, under license from Excellente, manufactured a line of guitars which were marketed as "The Kramer American Showster Series". These guitars were sleeker versions of the more traditional shapes of the day, and utilized Excellente's patented "tear-drop" body taper and "metal loading" insert feature to increase tone and sustain.(U.S.Pat.4,635,522). Fewer than 1,000 of these guitars were produced between 1988–1990, and the line was discontinued during 1990 due to manufacturing problems which began to plague Kramer during that time.