This much is quoted in Farnol, Jeffery. The Broad Highway. Boston: Little, Brown and Company, 1911, page 127:

A tinker I am, O a tinker am I,
A tinker I'll live, and a tinker I'll die;
If the King in his crown would change places wi' me
I'd laugh so I would, and I'd say unto he:
"A tinker I am, O a tinker am I,
A tinker I'll live, and a tinker I'll die."