You're right, Poplar Town Hall (or Civic Hall) £0.50 at the door 😀
The Billy Bragg appearance was really awkward because the keyboard player in his band, Riff Raff, wanted to join my band so invited us to the gig to see him play. I don't think he'd told BB though so when myself and the guitarist were invited up, I was like .... shall I? shan't I? but the overwhelming desire to be famous kicked in and up I went🤣 Thankfully mobile phones hadn't been invented so there's no embarrassing YouTube footage - Phew!