I did quite a bit of research into this song and as far as I could find there is/was no earlier Gaelic/Irish version. The origin as I know it is that the actor Peter O'Toole dictated the words to Dominic Behan in the early 1960's and it's that version which survives pretty much intact. It's possible of course that some previous trad Irush songs may have mentioned Carrickfergus or the tune way well have already existed, Behan was known to use some old Gaelic tunes for his songs
The story of the song, which I've heard from more than a few in Kilkenny, is that the 'rover'or minstrel, was from Northern Ireland, possibly an ex Soldier, who yearly made his way down the through the country usually ending up in Kilkenny. Where one year he met and fell in love with a lady there. he promised to come back and marry her, but when he did she had died. The Marble referred to Kilkenny marble, once the finest in Europe and mined in my home town, nearby Castlecomer. Most of the gravestones in KK cemetary and many pub and shop, church frontages are made of the same black marble