A Registered cover to Ealing franked 4.1/2d cancelled Field Post Office X 26 JU 29 - with the R No.124 APO S.40 registration label amended to FPO X. 

On the reverse a further strike FPO X and two London Registration marks. 

A little known date stamp, never used in WW1, Proud records in 1924 in Germany, but in 1929 the date stamp was used at the French Artillery camp at Birche (Saar), in Lorraine France on the Germany boarder. There is no unit allocation, however K&C notes record with the 13th Army on the Rhine at Artillery Training Camp. 

ID: D 24527