Ones that I can think of that never got a bilingual board...open to correction.
Headford Jct, Loo Bridge. Dooks, Listowel, Abbeyfeale, Newcastle (West), Ballingrane Jct, Rathkeale, Fermoy, Bruree, Newmarket, Mourne Abbey, Rathduff, Clondulane, Dunkettle, Little Island, Cobh Jct, Carrigtwohill, Midleton (cabin had a small version, ditto Killeagh and Youghal)
Blarney (both), Ballymartle (Kinsale branch), Clonakilty.
Early closures, Clifden branch, Achill branch.
Curiously the Muskerry got one GSR board (Western Road) as did the Passage (Monkstown) and some perhaps not all T&D roadside halts got them.
Manhattan, there's a Bagenalstown GSR board in Fitzpatricks Hotel.