No, Sean was correct.
On the Ghost Cars fan club disc "Left Hand" was recorded at the Olympia in Dublin. It's the sole performance to be released from the show, which is a pity because it was one of the best shows I've ever seen them do - and more than a little frustrating to know the entire show in on a DAT tape somewhere. However the majority of their return to Dublin nine months later at the National Stadium was released on the "Foreplay" fan club disc.
Only two Ghost Cars tracks originated at the Edinburgh Playhouse - "Love You 'Til The Day I Die" and "Better Be Home Soon/Frank's Dark Past".
My Ghost Cars CD has 16 tracks and no "20th Century Boy" track.
However there *IS* a nod to the T-Rex song on there, it's tagged onto literally the final seconds of a performance of "Tail Of A Comet" at the Guildhall in Portsmouth. If they performed a full cover of the song, it ain't on my CD so I'd love to see the liner notes you've got to figure out/correct the discrepancies.