Good Morning
Had a look for military records for Rees Stoke on Trent,and I'm not saying this is his father but may be worth a further look.
Edgar Rees born 1881 clerk enlisted Labour corps 1917 discharged physically unfit to serve.
Says he married a Margaret Evans at Register Office 5.6.1909 but now where ,and I can't find it.
Son William
Address 4 Wilson St S on T for father and 2 Newcastle Road Shilton for wife Margaret
Home 30.10.1916-14.11.1917
Suggestion he comes from Cardiff and her from Knighton Radnorshire born c 1888/9
Worth a look?
Ciderdrinker