I'm working on the cross-references for the "Penguin Book" Grey Cock at the moment and still have things to look up, but this one really does seem to fall into a sub-group of its own, as John said earlier, deriving from Child #77 rather than #248.  There are some broadside copies at  Bodleian Library Broadside Ballads;  here is one:

Willy O!  Printed c.1867 by W.Birmingham of Dublin.

Malcolm