It's always struck me that Newley's musicals were thinly disguised versions (rip-offs?) of classic pieces.
Greasepaint --- Sir and Chappie seem like variations on Pozzo and Lucky in Waiting for Godot
Stop the World --- Everyman
It's a Funny Old World, etc ---- Paradise Lost.
If only one of the shows could inspire such comparisons, it might be a bit far-fetched. But 3 out of 3?