Never heard the radio series, not living there nor on planet earth just at that time, ditto with the early TV b&ws but the b&ws are the ones I later saw most of, in re-runs. Not sure I’ve ever seen one of the colour episodes until today.

The series was known for its formulaic nature, yet well done, yet again with wooden acting, yet yet again … with ultra-politeness, which PDs liked. Jack Webb seems urbane but was the brains behind the outfit all the same, quite direct. And look who’s his sidekick here.