Rathlin Gaelic was quite similar to the Gaelic of Islay which survives to the present day.
Indeed, if I was to set about reviving Rathlin Irish, I would learn the Irish of Tory and the Gaelic of Islay in order to strengthen what can be learned from books and tapes.
You can learn a bit of Islay Gaelic daily by following Ionad Chaluim Chille on Twitter!
https://twitter.com/GaelicIslay
