Replacement of signs with GSR standard enamel was simply a mater of money. They would allocate a budget for a line and all stations would get it, while there were none on another line, just originals. Then, another small budget would allow replacements on a piecemeal basis for a while; on yet another line, therefore, they'd only replace those they had to - e.g. ones which got damaged or rotted. The Clifden, Achill and Killala lines never got a single one between them, and while the Foynes line mostly did, I don't think there were any between Ballingrane and Tralee. Sligo - Limerick was a mixed bag, mostly pre-GSR! Narrow gauge lines were also a mixed bag.