I've been away, but I will call the Gwyn Arms if you let me know the date. I have sent a PM to PW to let him know the contact number as I will be away 3 days this week too.
The Cwyn Arms is about five miles passed the Abercrave. When you see the Dan-yr-ogof caves on your left, turn right down a small side road 'there's a sign saying Gwyn Arms this way'
You won't be needing that newfangled GPS thingy, we fond it wiout even a map