>> The last phase was more or less just scratches.
http://irishmegaliths.megalithomania.com/zTinure.htm
Well, perhaps they're wrong, but these are thought to be Neolithic or even Mesolithic. These are probably considered older because they're more primitive.
Unfortunately, the shale surface they are (or were) carved onto is now gorse and bramble infested and may even have fallen off - it's impossible to say because you can't get near them.
