Having looked at more of the letters, was his wife Maisie?
The letter from 30 Sandgate Ayr of 5 Nov 1918 does appear to be signed Maisie Evans and refers to having been married to him on November (of 1917) in Ayr. He returned to Ayr from his officer training on 2 October 1917. The letter from Maisie does not seem to have been followed up anywhere.
You'll perhaps have noted that the letter from the minister in 1916 says he is the brother of Madame Laura Evan Williams and that he has three brothers.
MaxD
Yes, he had three sisters and five brothers in total - the more famous siblings being Laura, (renown Welsh operatic singer), hence why her name may well have been dropped into the letter; Elaine Evans, aka, Snookie - who was an actress, singer and director and Bessie, the youngest sibling. William, (One of those who had also popped off the radar), was actually born William Brown and I found him again in Cornwall with a wife and child; Stanley Ellis and Hugh George, both KIA in the Great War - and then that leaves, Richard, who I have lots of details on and John Evans - John and Bessie are the two that are now unaccounted for - cannot find anything on John after 1901 and yet to have a good look for Anne Elizabeth, (Lizzie).
I have to say, you have a very keen eye on deciphering the handwriting - excellent information you've given me to start looking for a marriage!
Thank you so much for all your help!
Take care
Michelle