G'day Mark,"Folk Scare" is just a wry reference (filched off someone else ... ) for what the record labels saw as the "Folk Boom" - and the folkies saw as the "Folk Revival" in the 1960s/'70s.
Colm O'Lochlain's books (Irish Street Ballads ... and More Irish Street Ballads ...?) were published in the '60s ... at much the same time as Patrick Galvin's Irish Songs of Resistance. I've seen copies of Galvin's book secondhand - but not O'Lochlain's ... I'm after a copy of each myself!
I doubt that they got the same commercial distribution as Irish Songs of Resistance, but Meredith often quotes from them in discussing songs of Irish origin. Mudcat's Master McGrath, with whom I have been discussing his rather more northern-focused book of Irish songs of the rebel times, obviously has a set, as he has sent a few photocopies of appropriate entries.
Regards,
Bob Bolton