As well as 'Grandad' by Clive Dunn. He appeared at the behest of the composer, Sussex's own Herbie Flowers who also almost as impressively knocked off the double tracked bass on 'Walk on The Wild Side'.
Dave Robinson certainly got as much work out of Kirsty as he could. She is on quite a lot of Stiff releases, so combined with the ToTP appearance, it is a natural assumption to make. Cher had a similar relationship with Phil Spector and is believed to be on, amongst other things, Da Doo Ron...
Kirsty mimed it on TOTP, but it's not her singing on the record.
However, she does sing backing vocals on Tracy Ullman's cover of her song 'They Don't Know About Us'. It's her, not Ullman that sings the piercing BABY! She's also on Billy Bragg's 'Sexuality' and The Happy Mondays'...