1) It's Part Two because Parts One & Two of the VHS I put up on YouTube earlier - they're right there at the side.

2) As for the source, I've no idea - it's a mixed bag of all sorts of odds & ends, these sea songs redited with quite dodgy maritime stills (why?) so I doubt the BBC had a hand in it. The MES clip looks like a rehearsal rather than a performance - the only footage of Ursula Smith I've ever seen...