If you look carefully at the base of the tower, you can just see the remains of the R and the E at the end of EIRE.
There is actually an historic aerial photograph of this sign too which the Military Archives have published on their social media/Flickr stream
Bing Image, collected January 2013
No Google Maps image for this location
This sign was linked to LOP58, given as Corraun, Co Mayo. It’s actually in the Currane estate, a little further east than Corraun I think and it’s not in the worst condition, The number is still in place, although slightly damaged.
Malin Head has been restored since these aerial photographs were done. You can read a report on the restoration here – the restoration was done in 2015. It looks beautiful, far better than it did when I saw it as a child.