Margarita - I can't see your "mistake" on the Maid of Amsterdam is anything but a quite reasonable variant, which in fact means the same as the "original. except I reckon that placing hi hand on her chest rather than the other way round is more likely what he'd have sung.

You don't think shantymen stuck to the same set of words do you? They improvised and adapted like blues singers. Read what Stan Hugill had to say about the shantyman's craft.

And they'd sing different sets of words sometimes out at sea as they would in dock - notably on Whip Jamboree, where there were verses Stan sung on a recording session where I was in the chorus, in between takes, that he would never put in his book or on record

Talking about blues singers - I sometimes wonder if the classical blues form actually comes out of singers applying the rule "when you forget the next line, sing the last line again."