Thanks, Charley. Haven't come across the dance.

Thing is, it seems to have so many different applications. "She's a proper juberju" suggests that she is something excellent ~~ from 'jubilee', perhaps' or 'jube-jube' the sugary sweet. But where would phrases like "watch her, catch her, jump up in her juberju", where it seems to be a part of the ship's rigging(?), or one of her boats(?), fit in with that?

Remain greatly exercised!!!