Susan,
Many thanks for the references to the Percy Mss versions. I wasn't aware of these online. What they demonstrate is that the ballad was quite popular among the high stratas of English society in the mid-18thc. Child chose to print as his A version only one of these versions dated 1770 and 1775 but at least one version online is dated 1765. These early versions bear the hallmarks of burlesque for me, despite what Jim says, the jig metre, the very clipped phrases such as 'And buried 'em both in a grave' remind me of the definite burlesque versions of Cowell et al.

Another interesting point is the correspondents mention 'the exact counterpart' of this ballad as 'Giles Colin'. Precisely. Giles Collins is another ballad that I think is a burlesque. It has the same ludicrous very clipped language and has some of the same motifs in it.