Hi Russ,
Great info. Continuing the subject of unknown units:-
Uffz Paul Pietsch is noted in CGAS as being killed on 01/6/1918 at Nivelles, Belgium. Unfortunately no unit is given.
I have seen an aerial photograph of FA A 217 dated 16/5/1918 where a Uffz Pietsch is noted, but the area being photographed is given as Dernancourt which is almost 160 kilometers from Nivelles.
If anyone knows where FA A 217 was based during these dates, it might help to determine if the Uffz Pietsch was serving in this unit when he died.
Of course he may have been transferred to a different squadron in the meantime...