In the process of looking for something else, I stumbled across a series of articles on the Blanket about Saor Eire (the 1960s group, not the 1930s group). I'm not sure how I managed to miss them when they first came out, but given my interest in Republican history I was very interested to read them. One thing that was mentioned in Bowyer Bell's The Secret Army that wasn't mentioned in these articles was a splinter group called Saoirse Eire. I don't know if that was a group that really existed or if it was just a couple of guys who gave themselves a name, Peoples Popular Front of Judea-style.
Anyway, the articles are A Little Known Republican Military Group: Saor Eire and three followup articles: Saor Eire, Follow up on Saor Eire, and Saor Eire again.
Saor Eire, IRA, Ireland, communism.