I could only rate this 5/10 mainly because of the atrocious casting.I do not accept Ealing Films could not cast this film in 1952 with more authentic Irish actors in the principal roles.Consider they casted these leads:John Mills, Dirk Bogarde (English) wobbly accents, Robert Beatty (Canadian) wobbly accent, Elizabeth Sellars (Scottish) wobbly accent.Ironically Eddie Byrne whom I always thought as Irish was actually born in Birmingham, England and Barbara Mullen was actually born in Massachusets, USA.A real mixed bag of actors and accents which completely destroyed the believability of this film for me.I suppose their drama academies had not taught them authentic Irish accents and had dredged every vernacular out of them in their quest for received pronunciation.
The part of "The Gentle Gunman" I enjoyed most were the verbal duels of Gilbert Harding ("What's My Line 1950s BBC TV version;Face to Face with John Freeman) with the actor who played old doctor O'Loughlin (from "A Night To Remember" 1958) and a Mrs Doyle (Father Ted) type woman operating the telephone exchange at an Irish post office.Film producers have an awful tendency to romanticise IRA type figures in films.