I’m once more very grateful to people who tell me about these things. I searched for Eask Head’s sign through the aerial photographs 7 years ago but could not find it.
Part of it is still in place but the sign itself is in really poor repair. All you can see is the closing E.
The nearest look out post to the Blasket Islands is Dunmore Head which is on the mainland. It was LOP number 38. There wasn’t a LOP on the Great Blasket that I was aware of and most signs were linked with the nearest LOP hence the classification. At the moment, it does not look to me as though the number is intact for this location so I cannot confirm absolutely.
Location on Google is clouded over.