Mis-filed (not indexed) in the SCO section of the WW1 Service Records (WO 363):

Arthur John SHINGLER, born Newport, Monmouthshire. Enlisted August 1917 at Newport, age 18yr, a Seaman. Discharged 1919. Reg Nos: 26835, 49147, 27695, 680421.

Anc****y, SCO, pages 58357 to 58372