ericferret . You are right of course! I've just realised I do have it off the shelf at the minute for modelling a Morane Parasol.
I was getting confused with the WW2 series , since in the end paper of this volume ( WW1 Vol5) is a reference to Bill Green's War Planes of the Second World War :
" In preparation:
Volumes 11-12 Bombers and Reconnaissance Aircraft (Gt.Britain to Italy)
Followed by other volumes dealing with the remaining combat aircraft in alphabetical order of the countries."
These were the ones of the WW2 series that didn't appear of course.
The WW1 Vol5 back dust jacket also states with reference to that series:
"Subsequent volumes will deal with fighter aircraft of other nations,followed by additional volumes on bombers, reconnaissance aircraft,seaplanes and flying boats,and miscellaneous types."