I met George Gilmore a few times in the 1980s when I was a boy living in Howth. He used to collect his pension and struggle up the hill to his cottage on crutches. He said his legs had been broken by "one of Dublin's famous drivers". His cottage was tiny, and I am not sure how he came to live there, or whether he even owned it. Even back then it was bizarre to live in a cottage without electricity, running water or even a road. Maybe in the West of Ireland, but to do so in a suburb of Dublin was very odd, and clearly his choice, but he kept it well, with a small garden. l used to ramble all over that part of Howth spoke to him once. said he loved living there because it was full of "pictures", the sun rising in the morning and the moon rising over the water at night.
When he died in 1985 the cottage was abandoned, and broken into several times. I was walking near the area and found some papers of his strewn about. There was material from the 1930s and 1960s, newspapers and political pamphlets, some Soviet propaganda. I thought I better collect them, rather than let them rot outside. I still have these papers and have offered them to the National Library. George was one of the founders of the Irish Republican Congress in 1934, a left wing organization and there some material from this. He was one of the leaders of the old IRA in the 1950s, before it began the murderous campaign in Northern Ireland in the 1970s-1990s, which he disagreed with.
There are plenty of sources about his life on the internet.
His cottage is still there. Last time I looked, it had been reroofed was being used as a stable for horses.
You can see it on Google Maps here
All the best.