Is this the last gig?

Is this the last gig - and maybe even the last song, that last rousing rendition of Light Up the Fire in front of 30,000 people at the Greenbelt Festival in August 1978?
The picture is taken from the Greenbelt 74-83 commemorative album produced by Myrrh records.
Sue McClellan is definitely wearing the same boiler suit as at Kamperland, a few weeks earlier and judging by her attitude may be leading the audience in the final singalong described by band member Pete Yates-Round.
Sadly the album does not contain live recordings. It is a great listen of Greenbelt greatest hits but the Parchment song is Light of the World from the Myrrh-issued Shamblejam three years earlier. Myrrh anthologised this track a number of times. With stunning electronic effects, it is probably the most sophisticated track on the album, if not the most fun.
Does anyone have any better pictures of Greenbelt 1978 - or indeed any Greenbelt appearances?