Ian Callaghan wore the number 7 shirt as did Brian Hall and Phil Boersma. I think even Ian Rush wore it (once) and Steve Highway also wore it but he wore number 9 much more.
Alum Evans, Steve Heighway, Albert Stubbins, Ian St John, Roger Hunt and Billy Liddell all wore number 9 but they wore whatever shirt was relevant to the position they played in. Liddell wore many different numbers. Oh and David Johnson also wore number 9.