"Sullivan, said that Brendan demanded that any royalties should go to Dickie Shannon, as he wrote the song"
This was confirmed in an article in The Irish Times a couple of weeks ago - it was part of an interview with an agent of Behan's.
Can't remember the details, but I'm pretty sure it said that Behan instructed the interviewee to send a cheque to an address in Inchicore, where Dickie Shannon was living in at the time - it stuck in my memory because that is where some of my family lived
Jim Carroll.