Ok, here's what I found but needs checking out. I'm wondering if he was in the services in Wales when he met up with Ruby Ball.
His birth registration
WILLIAMS, WILLIAM THOMAS mmn MILLICHOPE
GRO Reference: 1894 J Quarter in ST OLAVE SOUTHWARK Volume 01D Page 274.
His parents are Henry George Dwelling Williams and Frances Catherine Millichope, they married 29th March 1892--image of marriage on Anc*
William Thomas Williams was baptised 11th April 1894, born 24th March 1894
Image of baptism on Anc*
SS