I think the guy in the photo wouldn't have got a role in Bronco Bullfrog - his hair is too short! Did you actually audition? If so, what did you have to do?
I guess it could be John Thaw as he had been active in TV and films since the early sixties. A funny bit of trivia about him:
'He appeared in several episodes of the BBC police series Z-Cars in 1963–64 as a detective constable who left the force because of an unusual drink problem: he could not take the alcohol so often part of the policeman's work'.
IIRC, we all registered and were told we would be contacted if we were to be invited back... I don't know if any of us from up this way ever did get a 'call back' - I certainly don't know anyone that did.
Looking back, it may well have been a bit of a PR stunt to get the film some cheap publicity.
John Thaw was, of course, a Manchester boy - as was Harry H. Corbett of 'Steptoe' fame - so maybe in his early days he could initially have been involved - who knows?
Great actor(s) mind.
Edited by Ed Vaughan - 1/7/16 at 2:23am