Hi all!
In the last week I've found some more pieces of paper that my father has put together about his family. Jane Jones, 1834-1910, was his G Grandmother. It seems from a rough family tree that he's done, that Jane's parents were actually Benjamin and Jane Williams.
Dad's filled in one line of his cousins, descended from Jane's brother William Williams, born Llanbeblig 1840. He says that his mother told him all these details, and he knew these cousins well through his life (Dad's 84 now). So I'm sure he's got this right, and it confirms that Jane was born Jane Williams and was not related to the Evans family.
This Jane Jones, nee Williams, also had a sister Elizabeth, 1837-1924, who had a daughter Jane Annie. I've found this Williams family in both 1841 and 1851 censuses, living at Turkey Shore, Llanbeblig. All their ages match up with my father's and grandmother's notes, so this must be the Jane who married John Jones, my GG Grandfather.

However, the plot gets thicker, because Dad has also unearthed two bound copies of the diary of John Evans, Chandler (the younger)! These have been passed down through the family as well, and are in Welsh. My aunt had translated some pages before she sadly died a few years ago. It seems that this John Evans was not a family member, but a very close friend of John Jones.
The pages written about John Jones' death, found drowned from the May Flower in 1862, show that he was very upset.
Entry for 13 February 1862:
'A telegraph letter came to my father from John Jones, Diver, Bangor, with news that the body of John Jones, one of the unfortunate hands of the 'Mayflower' had been found. My father went to Bangor with the 1.15 train and telegraphed that the body was that of John Jones, Penllyn, the captain and he was taking him to the house of his wife Ellen Jones by 10 o clock tonight.'
Then the following day, 14th February:
'Examining the body and searching through his trousers they found his knife, hair comb, a 'ginger' and 3 shillings in his pocket. The dead is John Jones, Carpenter, Bangor Street, and he is in the house of Ellen Jones.
The body will be identified at 8 o clock tonight.
E.g.Powel Esq., coroner, examined the body of John Jones in the house of his brother, Hugh Jones, and it was taken to the house of his wife, Jane Jones, Bangor Street.'
17 February:
'Burial of John Jones, Carpenter, aged 29, Bangor Street, with a very large and respectful crowd in Llanbeblig. There were 20 flags carried by the seamen of the town. Ships in the harbour flew their colours at half mast. He was lowered into the grave by his brother Hugh Jones, his cousin Thomas Jones, Felinheli, John Williams, seaman, and John Evans, chandler, Greengate Street.'
I don't know here whether he was referring to his father John Evans chandler, or himself in the third person. It certainly sounds as though he was not related closely to John or Jane Jones, but knew them very well. It does seem as though these were two separate families who were close.
We know that this is the John Evans Chandler, because he talks a lot about making candles, and his father going to Liverpool to buy wax for the candles.
My only explanation for the odd M.I. on John Jones' son's grave is that it may actually say 'John Jones, Godson of Mr Evans, Chandler.'?