Knebworth 78 as broadcast on Radio 1 included Fountain of Salmacis, and The Lady Lies. Maybe others, just going from memory of what's on my tape of it.
The recording from '78 I have has 13 tracks, but it's fairly evident they were trying to avoid duplicate tracks when they're were putting together this collection.
Excluding the contents of the Old Medly, the only duplication I see is Drum Duet/Los Endos from '80 and '87.