The Chess Scotland History pages have excellent coverage of many old Scottish tournament series. One such is the Glasgow Congress series that started in the early 1960’s. It included at various times a principal ‘Invitation’ tournament and a Glasgow Junior International.
In 1968, in the seventh of the series, the Glasgow Invitation included one Irish player: Michael Littleton, Irish champion in 1962 (j.) and 1965. The Chess Scotland Game Downloads page has 47 of the 48 games, only added relatively recently (less than a year ago); none of these games is in ChessBase’s Big Database 2017.
The games have been compiled into a (short-form) tournament report here.
Littleton had a relatively disappointing tournament, finishing with 2/6 (+1 =2 -3), to finish 14th out of 16. The event was won by Michael Basman on 5/6, ahead of Craig Pritchett.