I think someone known (at least at the time) has admitted, if that's the right word, to buying it in good faith, for cash, and then finding it stolen when he went to look for it. And that's where the story ends:
Boat left on towpath by OP (person A).
Fraudster, person B , sells it to person C for cash, who moves it to Wigan and leaves it on another towpath.
Person D steals it, ostensibly off person C, but actually from person A.
There is a suspicion by some that either person B or C is in fact the same as person D, but as person E, who is a policeman, isn't interested, we shall never know.
Person A is happy at the Isle of Man watching motorbikes, which is nice.