Both just before my time. I saw them both (I believe) but don't really remember them that well as it was early days for me. Looked them up though and Napier got just the one cap for N Ireland in 1966 against W Germany so never played in a home international. Irvine on the other hand played and...
I used to quite enjoy the Home Internationals in the 70s especially if there was a Brighton interest which there was on the very odd occasion with Peter O'Sullivan playing for Wales and Sammy Morgan for Northern Ireland.