They had a small part in this film
http://video.google.com/videoplay?docid=356252404053826816&pr=goog-sl
...I hope I did that right, it's a film called "O'Donoghue's Opera" made in 1965, runs about 37 minutes and well worth a look if you approach it in the context of the time. If that url doesn't work look at a mudcat thread for "Ted McKenna" and you'll find a link.