I saw the show about Parky which had a clip of his interview with James Cagney and he just oozed stardom but interestingly despite every impressionist in the world who impersonate him coin the phrase "You Dirty Rat" in the interview he reiterates that he never said that phrase.
Watching that rerun of Parkinson clips reminded me of days gone by when Saturday night was a must watch time and Parky was the jewel in the crown when the people on the shows were "real stars" unlike to day when a lot , not everyone, are as JC might have said "Two Bit No Marks! "
Bill Owen's 1950s movie career was an attempt on the part of the studio to make him a kind of James Cagney-esque leading man from what I've read. Of course Owen dressed pretty smartly in real life, as did Kathy Staff. They wanted to make sure their beloved characters weren't the only thing people thought about them!