Genie,

Re: "Bless 'Em All"
Lewis Winstock was told by some Chelsea Pensioners that the song "was current" in the army during the last decade of the 19th Century.
According to Roy Palmer, it was written (or just first written down) by one Fred Godfrey of the RNAS, and the popular arrangement was written in about 1940 by Jimmy Hughes and Frank Lake.

(all culled from Roy Palmer's "What a Lovely War")

Regards

Walrus