In case anyone's interested, I've uploaded all 3 plays, plus a making of, without Dutch subtitles and with a 'Making Of', here:

https://www.youtube.com/playlist?list=PL_COTgjrCg-J2cl8biFjhcCjatezPsgQJ

But what I'm interested in, is tracking down the folk documentary that included scenes from The Nativity, including the 'lamb in the cot' comedy, and someone else playing Mary (pretty sure it was Dinah Stabb). I thought both were better than what are in my links.