Al Rex
Albert Piccirilli
b. July 13, 1928
One o the Bill Haley's Saddlemen former member, he left the band after playing bass on "Rocket '88" in 1951 and tried his hand at a solo career. When his replacement, Marshall Lytle, quit the Comets to form the Jodimars in the fall of 1955, Rex was persuaded to rejoin the group before deciding to quit the band once again in 1958, when he performed with The Kingsmen. By the 1960s Al continued to do occasional session work with his former bandmates.
https://en.wikipedia.org/wiki/Al_Rex
http://www.rockabillyhall.com/extra2.html#rex