I imagine that the ship 'Harp and Lyre' mentioned by Gurney was just a device to get a rhyme for 'fire'. These things happen often in broadsides and other folksongs for a number of reasons - ignorance and false national pride being the main ones. I only get annoyed when people accept these songs as historical documents. (Some of them have come down in a fairly accurate form, though, like the Benbow songs).

Again on the subject of ship's names - captured ships often retained their original name (unless the capturers already had one of that name).

The last two stanzas are significant, and are regularly used in versions of this song. Bristol was not a naval port and had no branch of the Court of Admiralty that was needed to award the prize to Captain Whatsisname (he had so many!). He'd already taken it past Portsmouth and Plymouth! But if you want to sell broadsides in Bristol...