A long time ago, a saw a spy movie on TV. It was dimly lit and the TV was black and white, and the cast seemed to be all similar looking gray men in trench coats. Since I couldn't tell them apart, and everyone was pretending to be something they weren't, the whole thing baffled me. I have always wondered what it was. I thought it might have been The Spy Who Came In From the Cold, but I saw it and it didn't seem right. Then I tried The Ipcress File, and that was all wrong. My most recent guess was The Mackintosh Man (1973).
It stars Paul Newman as a Brit (?) pretending to be Australian (??). He meets up with Harry Andrews, playing Mr. Mackintosh, and his secretary Dominique Sanda/ They are planning a jewel heist - a rather clever one. He pulls it off, and escapes by with the aid of a reversible Mackintosh - plain gray outside, with a tweed lining.
However, he gets caught, and sent to prison. Since I read the cover copy, I knew that he was actually a spy, who is looking to break up a prison escape ring called the Scarperers. So he gets scarpered, along with an agent who was caught spying for the Russians.
They are doped and kept out for days, then come to locked into an old house, somewhere isolated. Slightly domme-ish Jenny Runacre lets them know that they will be released after a week or so when the heat is off. Well, they let the agent go, but they know Newman is a cop, so they beat him up. But he turns the tables, and kicks Runacre between the legs - possibly the first time a woman gets it to the groin in cinema.
So he escaped, but he has lost the agent and the Scarperers. Then he spots politician James Mason's yacht and figures that he is behind it. So it's off to Malta, the yacht's next stop, along with Sanda. And so forth.
First of all, this is not a great movie. Even leaving aside Newman's ridiculous attempts at various accents (he plays Canadian as well as Australian and British), it just didn't hold up too well. Still, it starts well, with the diamond theft, and we do get some nice Valletta locations.
Second, it is full of British character actors whose names I didn't know, but whose faces were very familiar, probably from BBC TV shows.
In conclusion, this is definitely not the movie I remember. For one thing, there is only the one scene with the Mackintosh (as opposed to Mr. Mackintosh, who dies offscreen). But also, I distinctly remember a shootout in an airplane hanger, or possibly warehouse - where everyone was indistinguishable in their trench coats. I'll keep looking