Thanks for this; its been very useful and made me rethink things a bit.
I was aware of this Lewis David at Ffoesgotta. Firstly, because in the National Library of Wales catalogue, there is a reference to a tenancy agreement (I think in 1749) to a Lewis David (from Llanybydder) starting the tenancy at Ffoesgotta. Then the first page of the Llansawel parish register records the baptism of Lewis David's daughter Elizabeth in 1751, with the birth of son Lewis two pages later in 1754. To get earlier than this for the older children, I think I would either have to go to Aberystwyth to use the available bits of the Llansawel Bishops transcripts at NLW, or possibly look at LLanybdder registers . Finally there are the wills.
But my problem was (and I think still is) that I am not really been sure if this Lewis David and his descendants are truly an ancestor - because I don't fully understand the patronymics system of names and how it was used at this time.
My reckoning was that the son Lewis baptised in 1754 would be named Lewis Lewis. Certainly there are subsequent records of Lewis Lewis in the wills and then at the neighbouring farm Pantyiauiau, and finally being at Ffoesgotta in the early 1800s and being buried in Abergorlech in 1817.
I previously discounted this Lewis as the ancestors of James David, as I didn’t think he could be the father of James David as he is called Lewis Lewis, not Lewis David. I didn't think of the possibility of the brother with the names reversed.
James Davies (my ancestor) was at Ffoesgotta in the 1850s as a tenant famer. From parish registers and censuses, I think he was born at Hafodwen, farmed at Banc when his children were born, then lived at Rhydglyn prior to living at Ffoesgotta. He was a deacon at Bethel chapel in the 1850s. His son John Davies farmed next door at Blaenresgair from about the 1840s and the Davies family are still at Blaenresgair.
I knew about the wills you mention but couldn’t previously really relate them to "Lewis David" the father of James. However reading Lewis David’s 1798 will again (more carefully following your email) makes me rethink some of this, and perhaps as you suggest David Lewis could be Lewis David.
In the 1798 will Lewis David (senior) leaves “£5 to my son David Lewis” and then later in the will leaves some livestock “to my son Lewis”. Harry Lewis’s will leaves “£10 to my brother David Lewis” and then later makes a bequest “to my brother Lewis Lewis”.
This makes me believe that Lewis David Sr had four sons Harry, Thomas, David Lewis, and Lewis. Could this David Lewis be the Lewis David referred to as father of James in 1783 - or would he be called David Lewis Lewis?? This is where my knowledge of Welsh naming traditions lets me down. Do you have any advice / experience with this? Does it happen that the names could be reversed?
I’d really appreciate help on this point.