“He was so good at it (accents and imitations) that many did not recognize his normal appearance.”
Martin Landau used to be that way during his days with Mission Impossible. He and Barbara Bain used to be the ‘it’ couple for the most cool and urbane American spies.
I got to meet Martin at a DragonCon a few years ago.
He seemed personable and a likeable guy to me.
There’s a current film on Netflix called “Silver Skies” that stars Barbara Bain, George Hamilton and Valerie Perrine (made fairly recently). It was interesting to see how they aged.