Who would be the last Welsh referee who achieved notable international success/ Or indeed Irish for that matter? I'd never really considered that until the above post.
Rodger Gifford at a guess?
Keith Cooper was highly respected domestically and I'm sure was FIFA. How much international recognition he received is, however, something I don't know.
Keith Burge also had a good international career, a regular in the champions league, UEFA cup etc. in terms of Ireland Leslie Irvine was a regular, although he was Northern Irish, as was Alan Snoddy.