Steve56 tells me that Landscape were on this recording with an all clapping and long tune. I think it could be the one that starts at 17:39 into the track. This is the same group that went onto have a hit called 'Einstein A Go-Go'. They did not release an album until 1979, but released two EPs before that and four songs/tunes for a John Peel Session.
24 minutes into my recording, Fluff says 'in the next two hours of the Saturday Show, we'll seek out Ozark Mountain Daredevils, Clash, Genesis, Brand X, Rich Kids, Pocus, Sex Pistols and Be Bop Deluxe'