> At least it's unlikely a print version could have been used.

Why is it unlikely? Mr Stockton's version looks to me as if it derives fairly closely, via oral transmission, from the 18th C. print version. Stanzs 8 and 9 and the extra two lines at the end of stanza 4 are new (at least new in relation to the 18th C. version -- do they appear anywhere else?). Otherwise most of the differences are the sort of minor variations that could be expected if the song had been in oral tradition for some time (including the change of location from Gosport to the more familiar London). There are two incoherent lines, which look as if they represent mishearings of lines that make perfect sense in the broadside: „For pardon sweet William is the worst of all men" could easily come from "O perjurd creature! the worst of all men!", and "And pled forth the paymount for to plough the whole sea" suggests the sounds of "Bedford", "lay out at Portsmouth", and "bound for the sea" in the equivalent couplet in the broadside. Otherwise the biggest departures I can see (apart from those in stanzas 4, 8, and 9, of course) are in the last two lines of stanza 10, but I also notice that these fail to rhyme, as if someone along the way has been trying to reconstruct lines in the broadside version that they half remembered and hasn't quite succeeded.

In particular the meaningless "pled forth" in stanza 7, points to this version deriving from one that mentioned the Bedford at this point, which means it was either the text as we have it on the various C18 broadsides or something very similar, not an earlier version song from before the time that the Bedford and Charles Stewart entered the story.

Of course that doesn't mean that there wasn't an earlier version independent of the broadside, just that I don't think Mr Stockton's version is evidence of it.

On the other hand, even assuming, for the moment, that the ballad was,as Fowler argues written by someone who had heard of an event concerning the Bedford in 1726, I would agree that it's most likely that the story would have been influenced by recollections of other ballads and stories of murder and supernatural revenge by the time it got into print - in fact that would most likely have been happening while it was still just shipboard gossip, if that's how it started.