Building a little on the link to Come All Tonguers, there's also a link to a variant of The Golden Vanity. Here's Wellerman:

> There once was a ship that put to sea / And the name of that ship was the Billy o’ Tea / The winds blew hard, her bow dipped down / Blow, me bully boys, blow

Here's one version of The Golden Vanity:

> There once was a ship, and she sailed upon the sea, / And the name of the ship was the Golden Vanity / She sailed upon the lowland, lowland, lowland / Sailed upon the lowland sea

The question is, which version of The Golden Vanity is this? I checked Traditional Tunes of the Child Ballads and these lyrics vary quite frequently, going back into the 19th century. I'm not sure if this information narrows down the possible dates of composition, unless if we can make a strong argument about when the ballad was likely to hit New Zealand.