I finished watching series 1 of Secret Army (I've been at home sick for most of the last four days) and afterwards I checked Wikipedia to learn whether ( largeish spoilers )
I'm skimming through random shows with Christopher Neame in them. Here's a screenshot from an episode of The Protectors, which aired in 1974. Neame played a baddie in stylin' 1970s fashions (and, from what I could tell, the same car as Peter Guillam in Tinker, Tailor, Soldier, Spy).