The two main Atari factories for assembling arcade and home systems were in Tipperary town, and Raheen in Limerick. I think Tipperary was the arcade factory as I recall there was an amusement arcade in the town and we were told we had the arcade machines first and a mate had the high score on one of the machines, and Atari said he had the highest score in the world. That was before Twin Galaxies and was probably just local waffle. Tipperary factory started in the late 70s.
Ardkeen was used later for cabinets only I think.
The Tipperary factory eventually became used for one of the largest mushroom producers in the country, the ones you would hear talking about how Brexit would be a disaster for them.
The Raheen factory was taken over by Dell in the early 90s, when it became EMF01. Dell took over the old Wang plant in Castletroy after AST had it, as EMF02.