One I recently re-watched after several years - "The Long Duel" starring Yul Brynner as a tribal chief, and Trevor Howard and Harry Andrews as British officers on both ends of the spectrum of colonialist reasoning.
Not too bad, and it's got a nice train ambush scene. None of the greats, though, either.
Addendum: Not North-West Frontier, but British India - "Bhowani Junction". Really liked that one.