Is it possible that he may have worked either in Silvermines, or Hollyford, or some place else where there were mines in the mid 19th century? It's about 4 1/2 miles, straight line distance, between Cooneen and Silvermines.
Hollyford's copper mine operated periodically between 1837 and 1862. Brief history with map showing location of mines
https://www.mindat.org/loc-294786.htmlMining at Silvermines continued until 1874. Metal prices dipped in 1850s, miners weren't paid and went on strike.
Events at Hollyford and Silvermines may have caused your GGF's brother's move to England in 1850s and your GGF's emigration to Pennsylvania in 1865.
Miners in Britain relocated when their particular industry was in recession or their local mines were worked out. e.g. Cumberland iron ore and slate mines attracted Irish people and Welsh coal miners; some Cornish tin & copper miners went to coal mines in northern England.
Walking 4 miles to work and home again after was nothing for a man who was fit enough to work in a mine. It would add an hour to the start & end of his day. Children worked in mines in Britain, some of them very young, and in testimony to a government enquiry spoke of walking to & from work almost asleep, holding their father's hand or being carried.
Was there a railway line at the time? When did Nenagh-Tipperary line open? 19th century trains had 3rd class "carriages" for working people. They were open trucks at first and were later roofed to keep rain off. Some of my English ancestors were stonemasons and quarrymen; the first railway line connecting their village to the nearest town was constructed to carry stone before there were passenger trains; some workers travelled in trucks on top of the loads - a risky journey as stones sometimes slipped.
Your ancestor might have lodged near work, perhaps with a workmate's family. People were used to sharing a bed. If there was a night shift at the mine a bed could be occupied in shifts.