Was that the only clip they could find? Was there nothing else, no evidence of an act beyond the catchphrase?
In the mid 80s, he hosted an unscreened pilot dating show called It's a Hoot for London Weekend Television. The series was eventually re-titled Blind Date and hosted by Liverpudlian singer and entertainer Cilla Black. In 1991, Duncan appeared on the ITV comedy panel game show Through the Keyhole. 2008 saw him go out on tour as part of the Ricky Tomlinson Laughter Show. Norvelle spent the 2009 pantomime season playing Buttons in Cinderella in Doncaster, South Yorkshire.
In 2011, he appeared on Celebrity Come Dine with Me with Sean Hughes, Gina Yashere and Paul Tonkinson.
Health
Norvelle was hospitalised in 2012 after suffering a stroke, leaving him paralysed down the left side of his body. After nine weeks in hospital, he cancelled his summer season with comedy duo Cannon and Ball, and was replaced by Stu Francis.
I mean, sad times about the stroke, but his career details aren't exactly screaming "massive star". Outside of alternative comedy, there are plenty of names - Cannon & Ball, Little & Large, Russ Abbott, Les Dennis, Barrymore, etc - who could be said to have been big stars in the 80s.