I think I may have found it on Tidal. Similar cover, same recording Co (Phase 4). Unfortunately there’s no performance date on the tape box, and also no mention of Robert Farnon.
Tidal says performance was 1965, which would be a possible date for the tape.
https://i.imgur.com/ESeZQwF.png
I’ll try A/B (volume won’t be matched) and see what I hear later this week. I’ll try with both xtr and minringFIR.