> the bequests are not part of the print versions (except for the "seven ships" stanza).

But maybe a case of the exception that proves the rule. As far as I can see, the seven ships in the Forget-Me-Not Songster version and the similar stanza in Child C are not actually bequests left by the dying lover like the gold watch, tears, blood, etc., but promises of the wealth that Barbara could share in if she would accept him. The Annandale versions mentioned by C.K. Sharpe sound the same: "… containing numerous magnificent offers from the lover to his mistress—and among others, some ships, in sight…" (quoted in The Scotish (sic) Musical Museum, 1839 edition, vol. III p. 300, available at archive.org). We'll have to wait and see what the Peter Buchan MS text reveals if you can get a copy of it, but so far the ships look like part of the wooer's attempt to win Barbara by impressing her with his wealth, before he falls sick, not bequests left to her when he knows he is dying.

By the way, on the same page of the SMM where C.K. Sharpe is quoted, there is a four-stanza military parody of BA from 1752. (I think this one really is a parody, not a burlesque.) The model seems to be Ramsay's version or something like it – it starts "It fell about", which seems to come from songs with a Martinmas setting (for example "Get Up and Bar the Door"), although it's not actually how Ramsay's first line is worded (does it suggest that Ramsay's text was subject to a bit of variation in singing?) and later on has a line with "dinna ye mind" like Ramsay's accusation stanza.