He teamed up with other comics, such as Honest John Gilbert, Maurie Fields, and Val Jellay presenting comedy sketches in between the musical items.
Recycling his vaudeville shtick, Heylen specialised in stooges prone to cheekiness, drunkenness, pratfalls and spit takes.
Heylen was best known for his role in A Country Practice, as the RSL club manager, barman and chef Vernon 'Cookie' Locke, who he played from 1982 until 1992, alongside Gordon Piper as his mate Bob Hatfield.
Heylen was written out of the series in 1992 alongside Gordon Piper), as the producers wanted to concentrate on a younger cast and an updated formula.
Davern would later regret dropping Cookie and Bob, as they were two of the show's central older characters who provided many of the comedy scenes between the more dramatic storylines.