James Garner & Donald Pleasance don't escape. Pleasance is shot and Garner is recaptured. James Coburn is led to safety in Spain by the Resistance, and Charles Bronson and his mate (whose name escapes me) manage to get aboard a ship.
Just looked it up. the answer is Charles Bronson .... Flight. Lt. Danny 'The Tunnel King' Velinski, John Leyton .... Flight Lt. William 'The Tunneller' Dickes and James Coburn .... Flying Officer Louis 'The Manufacturer' Sedgwick.
John Leyton and Charles Bronson escaped by rowing boat before boarding a neutral ship. James Coburn was led across the Pyrenees to Spain by the Resistance - James Garner almost made it, but the plane he stole ran out of fuel and crashed just before the Swiss frontier.