I've been labouring on a 6CD 'Bert Jansch at the BBC' box set (1966-2009) set, for release next year some time. The 'holy grail' of the missing audio is this one:
Sounds of the 70s 2/8/71 and/or 23/8/71
I have none of these 5 songs - some very rare in his repertoire
The Sequence 11/5/73 is also missing in full, and re: Night Ride 18/12/68 - I have only two of the six tracks.
Happily, there are many survivals beyond the remit of Ken Garner's books (in which all three above comprise the BJ listing). But if anyone can supply any of the above... wonderful! :-)