Good news: the cassette deck is up and running. At first I thought it was completely dead, because no panel lights came on (it must have had panel lights, right?). But actually it seems to be working fine apart from the tape counter - which assumedly is on a separate belt.
Bad news: the recording sounds pretty horrible. When the percussion kicks in (and there is a lot of percussion), the bass is loud, boomy and distorted. So I’m not sure we’re going to get much out of this exercise, but having got this far I might as well complete it.
Actually the recording was made not by me, but in my presence in a friend’s room at our university halls-of-residence, because he had a better receiver than me at that time. But clearly not good enough!