As I understood it from an interview by Alan Bell,some years ago, Gordon Wharmby was auditioned for the part of Man on the Roof, but he was so good that he was then asked to try instead for the part of Wesley Pegden in Car and Garter. This was not his first appearance in the show though, he was an extra in 'Forked Lightening' as a man on the bus when Clegg was trying for the second time to take his bike back to the shop. You really need to watch very closely to spot him. I got this info from another quiz set by Mr Bell.