Joe, as far as I can see it's a variant of 'Polly-Wolly-Doodle-all-the day'. We used as kids in the 50s the exact tune for reciting the alphabet and this from my mother born in 1923. (Hull, Yorks)
as in A-B-C-D-E-f-G
H-I-J-K-L-M
N-O-P-Q_R-S-T-U
V double-u-X-Y-Z

It also could be related to the last part of the tune for singing limericks, and the Music hall song 'The Hole in the Elephant's Bottom'.

Regarding the PC issues broached here, I have some empathy with both sides of the argument. First I would not encourage anyone to sing it as it stands in today's world. BUT, as an item for research, which is my forte, I would say threads like this need to be kept as repositories for versions. Once you cancel history it has a tendency to repeat itself.

If you start censoring items like this on Mudcat you'll end up with nothing but the anodyne syrupy stuff. My group a few years ago put out a CD of whaling songs. These are historical records and in no way do they mean that we as a group condone whaling in the modern world. Also in my next book I am contemplating including several hunting songs as part of historical records of our county, but that does not mean that any of us involved support hunting in any way, and we will forcefully present that view in the book.