Sonic Boom do nothing with their sources, so I suspect the FLAC already shared will match this effort (the Poetry Hour disc is identical to the audio shared here and elsewhere).
They have probably ripped the late Adam May's audio from his video or used the soundboard FLAC from ST (the one debated about re: overdubs).
I don't know where they got the information about radio broadcast from - seems like invented justification.
To the best of my knowledge, all audio comes from soundboard and was part of the documentary - perhaps it was destined to be used elsewhere, but that's never been mentioned until asserted by this release.
I will put the FLAC in the downloads section if anyone wants it.
Passions assert the BBC have rights to the audio, so that should tell you about the validity of this release. Other collectors will have better experience with Sonic Boom products, it's not something I collect myself (especially as they bring nothing new to the table).
Oh, and here's the bit they will have sourced from a video of CH4 tv:
Regards,
FWD.
(Edit: what Cornflakes said)