Jim,
The name of the OP looks familiar as someone who writes on balladry. Senility allows me to disregard things like posting dates.

It would certainly seem that 'Skin and Bones' derives its 'worms crawling' line from AAFI. I'll have a look at the burlesques and see if any more of 'Skin and Bone' is derived from this.

I'll also have a look at the relationship between all 4 pieces as I have plenty of versions of all 4, i.e., original, burlesque, song and rhyme. It might throw up an interesting progreesion. The most likely order of descent is as given here.