My Grandfather Albert John Alliston Godwin (b 1878) served initially in the 6th Bn East Surrey Regt - we have two photos showing their distinctive cap badge. But his medal roll card shows him as a Sgt. in the Middx. Regt.No 235372. He had the British War medal and the Victory medal but neither of the Stars, so presumably he didn't go abroad until 1916 or 17. How do I find out which Bn. of the Middx Regt he was in and when he went abroad? The reference alongside his medals is E/1/102B41 page 6973. What info am I likely to get by visiting Kew? He was apparently gassed but managed to last until he was 77. Any help much appreciated.