Robert,
Given I have found this posting from 1999, I am hoping you may have made some progress in your searh for Kyffin from N.Wales, and that albeit a long shot you have picked up on connections to Denbighshire in the person of a William Kyffin (including the usual spelling variations) born circa 1841, who married 1867 a Sarah Griffiths, and had seemingly one child John Kyffin circa 1875. Sarah appears to have died young in 1885.
I am presuming that there cannot be too many Kyffins around, whereas there are thousands of me which is Davies.
If you can help would appreciate a mail.
best regards, peter davies,
www.peter-davies.org