You have me convinced Steve, however the same 5 verses were printed in "Songs of the Ridings" collected by Mary and Nigel Hudleston. This quoted Arthur Wood of Middlesbrough.
The same source is quoted in the New Penguin Book of English Folk Songs, I believe these were collected around 50 or 60 years ago, your references seem much earlier than this.
I would agree with your logic about being written outside yorkshire, my own logic would also indicate that the song is based on a real person and real events, otherwise why be so accurate?
I notice a note on the front page of the "Songs of the Ridings" (purchased from Ray Padgett), quoting "Special thanks to: Steve Gardham", I also offer my thanks as this publication I find most enthralling.
I have also heard Ray sing the 7 verse Rotherham Version as is on the Yorkshire Garland site.