The 13th Field Regt was part of the 3rd Div and fought through D Day. On 6 June 44, they fired their 105mm self-propelled guns from the landing crafts on their way into the beach. At war's end, the 13th served as part of the CAOF in Germany (note the CAOF patches on the tunic).
I have no idea why someone wrote DF on each patch? Does anyone know what that might mean?