Thanks for that link, M.
Some generations and brothers in the Winstone line of my family were both stone masons, and, by the use of this symbol on their graves, it looks like they were also freemasons.
They were not related to the part of my family whose gravestone in Llanon I am querying - that is until my grandfather met my grandmother much later!
In english, your translation does flow better with the rest of the inscription than the quote from the Psalms.
After the words "Hauwyd Goleuni i'r Cyfiawn",there is a comma, then, after the engraving of a Bible, it says "er serchus gof am David Williams...." which I believe is "in loving memory of David Williams...."
(I did try to attach a photo with my post but unfortunately couldn't do it.)
Do you think I am reading something into their having a Bible on the grave plus these words. It looks just like a closed, old welsh family bible. I am only guessing that David Williams might have had a role in the church based on this gravestone. The burial is at the parish church.
But maybe I have not seen enough graveyards! I have seen loads of angels!!
His daughter was a female servant to the vicar at the time of the census in 1851 but that doesn't mean anything in itself of course.
Many many thanks for taking the time to reply to my post. I have struggled over this translation before realising that I could ask fellow Rootschatters for their help on this.
Thank you everyone.