As well as the Great Train Robbery, this series seems inspired by the episode 'The Great Plane Robbery', from 'Gideon's Way' in 1965. The robbery, and the use of the point of view of the various gang members, are remarkably similar.
Despite being a major mini-series, because this was filmed and originally broadcast in black and white, just 3 months before the UK television networks moved to color, this show had limited re-broadcast appeal thereafter. It was repeated again in a late evening slot in 1971 and then not seen again for over 50 years, until Talking Pictures TV screened it again in 2023.
This mini-series was clearly inspired by the "Great Train Robbery" of 1963, in which about £2,500,000 was stolen by a large gang; it took years for the police to track them down.