This is his marriage record, 25 Dec 1917, but his occupation is just given as "Private in HM's Army", no specifics of regiment, but at least we know his rank now:
https://www.ancestry.co.uk/interacti...63137314/facts
His address is given as Elizabeth Cottage, Lea Valley, and his bride's (Phoebe Nora Jackson) as 60 Southwold Rd (Hackney).