As they say in this trailer, Michael Caine walked into stardom with The Ipcress File. Wasn't he was already a name by then?
I may go back and read some of those old spy novels. The Bond books were painful. Eric Ambler was great. I liked John Le Carre before he went off the deep end. Have not read Frederick Forsyth or Len Deighton in years. Am currently a major Daniel Silva fan. And, of course, there is Alan Furst whose books transport you to Europe in the Thirties.