Hi, I have just read your post dated May 2009 I think you should take a look at this link it has been very helpful for me in my research of the Morgan's (Llandeilo bridge builders) and my Phillips family all from around the Glanamman area. I had to register for Roots chat so I could send you this link.
http://www.genuki.org.uk/big/wal/GLA/Daviesbook.html It is a book David Davies's Book
'David Wm Davies the son of William Davies llwunphelish was Born in hirwain in the Parish of Penderain in the county of Breconshire in March 28-1828 ' (p7)
Here is a separate name index
The author commences on November the first 1854 by stating that he is writing a Llufer Cofadwriaeth (Remembrance Book) based on the genealogy of his father William Davies son of David J Davies of llwunphelish near castellnedd (Neath).
[There is a farm called Llwynfelis on the 1841 census in Dylais Lower hamlet, near Neath, at that date there is a Jonson family living there.]
A copy of the original book is deposited with the Family History Centre, Salt Lake City, the original depositor is unknown, a descendant will be given the original.
Its contents were transcribed by Lucy Bodily and proof read by Darris Williams
Let me know if it helps? Or you may already know about it.
Regards Janet (nee Morgan Phillips)