Although almost every copy of this has an un-laminated cover, a very few do have the front laminated. These seem to be even more susceptible to sun-fading. Labels seem to vary and some later issues are dated 1974 despite the original 1972 issue date.
On further investigation I'm coming down on the side of 1972. All of the early Cúchulainn records were from 1972 onwards so this was definitely NOT first issued in 1974. This can only be because it saw more than one issue. It was quite popular at the time and sold more than some other records on the label later on.
In addition, I have a copy which is signed by Geraldine and Tony Kearney and a dedication dated "Christmas 1972" which rather suggests that it was not originally issued in 1974. Original issues have completely different labels and, as NBoldock suggests, no date on the label.
What this record also makes clear is that Oakdove is the pseudonym for Tony Johnston himself. I assume it was his publishing company, and therefore where he did an arrangement he frequently used Oakdove rather than his name to claim royalties.