Both. He joined the GSWR in 1900 or 1901, and retired two weeks into the CIE era, having been in Inchicore throughout the 20 years of the GSR.
In terms of "might have beens", information passed down through the family included the above which I referred to, and a few other odds and ends, like a production run of Drumm trains, early talk of exploring other forms of electrification, and a specialised lorry design for carrying turf! Another was a standard design of 3ft gauge coach for the T & D, WCR, & C & L. Had this come into being, I believe it was to be based more or less along the design of the standard C & L balcony-end coach. However, it chould be added that this is pure speculation and no plan was ever drawn up, or design made; there was no money.