I really tried to!
Today I received an answer, and look:

Dear Elvis,
Thank you for taking the time to send in your query regarding "Carrighfergus".   Loreena is away from the office at this time, preparing for the release of her new album next month, and so I haven't been able to discuss your query with her. I did a bit of research, though, and found this: http://www.mudcat.org/thread.cfm?threadid=16707
Perhaps you will find something interesting in that discussion of the song.
Best regards,
Stacey.

Well, there is not an appropriated answer, but shows that this topic is really meaningfull! =)