One thought, no a couple thoughts. How odd it would be for a song sung in the custom of sailors would be heard in Liverpool by a Irish laborer, taken back to Liverpool been adopted into a very different singing tradition & then not only be taken into that tradition but then have another song grow out of it & that be exceptable enough to have survived while the orginal died off???

I think that it's possible but highly unlikely & nothing more than a wild guess.

Think of the possibilities
A song sung in Limrick going to Liverpool & being taken into, again a very different tradition, being adopted into that tradition but nearly disappearing in the tradition of it's origin. If it weren't good enough to nearly survive in it's birth place why would it be good enough to survive in a foriegn tradition??

I think that's also possible too, but again highly unlikely & is, again nothing more than a wild guess

But it is a sand pit worth digging around in.

Barry