I have it on a compilation LP called "Irish Folk hits" on the Marble Arch label, MAL 735, produced in 1967.
The Curragh of Kildare is indeed The Johnstons' recording and is listed Trad. arr Moloney and Johnston. This accords with Felipa's post above apart from the spelling of Moloney (Maloney)and gives you a date.
Unfortunately not much else in the way of sleeve notes, as was the fashion in those days!