The Flying Scot (1957)

The Flying Scot
Crime, Drama, Thriller
A gang of four would-be robbers plans to steal a fortune in currency hidden aboard the "Flying Scotsman" in a railroad stateroom by cutting through the wall of the adjacent stateroom, but find themselves up against numerous unexpected drawbacks, including interference by their fellow passengers.
Starring
Lee Patterson, Kay Callard, Alan Gifford, Margaret Withers, Mark Baker, Jeremy Bodkin, Gerald Case, Margaret Gordon, John Lee, Kerry Jordan
Directed By
Compton Bennett