Peter O'Toole and the Young Sick Lover

I have had a telephone call (this afternoon) from Peter O'Toole's agency giving the following information concerning how Peter O'Toole came to have this song to communicate to Dominic Behan:

Peter O'Toole heard most of the song, words and tune, in 1946. from a Niall Stack, who called it Molly Ba/n - the agent said P O'T spent his childhood in Kerry so we assumed that was where - and it fits with the name used by Behan, which is otherwise inexplicable: "The Kerry Boatman."

Peter O'Toole's said that his version was augmented and altered later from a version sung to him in 1957 by the actor, Richard Harris. [This is a very stagey story.]

Peter O'Toole remembers singing the result to Dominic Behan who wrote it down.

There is thus a linear connection between Young Sick Lover, Molly Ba/n and "Carrickfergus."

Would there be any sense in asking Peter O'Toole to deconstruct what he now remembers?

I'm thinking of contacting Richard Harris' Agency - any better ideas?