He did appear on TV. In the early 80s, the BBC did a show called 'I've got a Secret' or something similar, and it was [God help me, I can remember this] hosted by Barry Took. The usual panel of B-list TV celebs had to guess the unusual secret of the guest. It was in the early evening 'jolly family quiz-type programme' slot the BBC had in pre-Eastenders days.
The Alkemade story had featured in one of the war comics, probably Victor, (of which the 9 year old Archimedes was an avid reader) a short time before the programme aired, so his appearance stood out in my mind; indeed, apart from Barry Took being the host, it's the only thing I can remember. Nick Alkemade gave a very deadpan account of his experience, to the general astonishment of the studio audience and the guest panel.
The BBC might have kept a copy, so perhaps....