Conversation so far:
What does Sky and Trees and Agit-Prop Records have to do with Chumbawamba?
Chumbawamba had begun to release material using the vinyl format on their own Agit-Prop record label, which had evolved from an earlier project, Sky and Trees Records.
Is Sky and Trees the name of one of Chumbawamba's singles?
Sky and Trees was Chumbawaba's own Agit-Prop record label
What other material did Chumbawamba release under Sky and Trees?
Be Happy Despite It All, It's Up To You, and Let Us Show Them Our Hearts

Question: How many records did they sell under that label?
Self-contained rewrite: How many records did Chumbawamba sell under Sky and Trees?