- A Waiter in April 1967
- A Delivery Man in June 1968
- Dougie Bowker, owner of The Capricorn club in March 1973
- Jeweller Donald Anderson in February 1978.
Dudley then went on to appear as regular Bert Tilsley from January 1979 until July 1983, shortly before his death. His stint on the programme was fraught with controversy when in the early 1980s he pleaded guilty in court to attempting to pick up men in a public toilet (known as importuning.) Producer Bill Podmore and Granada stood by him and he was let off with a £200 fine, but he was charged a few months later with the same offence. This time he denied the charge, claiming he had been set up by the police, and chose to be tried in Crown Court even though it would generate considerable publicity. The judge in the case ordered a retrial after the jury was unable to reach a verdict.
Dudley suffered a stroke and lost the use of his left arm and a storyline was written to explain why Bert Tilsley's arm did not function properly. In 1983, Bert was written out of the show to allow Dudley to prepare for his retrial, but suffered two heart attacks and a stroke and died before it could take place.
Peter's other television credits include The Dustbinmen and Crown Court.