According to his Granddaughter, "W.G. Thomas was never known as William, always Geoff within the family, and it's Geoffry, not Geoffrey. To his contemporaries he was often referred to simply as W.G.
Geoff took up painting after the First World War ended – possibly as a healing therapy from war experiences. It is interesting to note that the WW1 soldier poets C.S. Lewis, A.A. Milne and J.R.R. Tolkien all wrote stories for children following their wartime service in the Army.
Geoff supported other young artists at that time including the potter Basil Matthews. Most of his paintings are of North/mid Wales - as he returned there in his vacations - and some are of the industrial midlands, where he lived."
W.G.'s Granddaughter has sent me some photos of some of the works the family have which were done by him.
I have written a post about W.G. Thomas for my Weblog, Forgotten Poets of World War One:
https://forgottenpoetsofww1.blogspot.com/search?q=W+G+Thomas