Pictures of Issoudon show a great variety of aircraft.
The French trainers were N80, N81, N82, N83. See:
http://mars.ark.com/~mdf/Nieuport_id.html
The training facilities were also supplied with small numbers of front line fighters and recon/bomber aircraft.
As you mention, Caudrons and Nieuports. I've also seen
pics of Sopwith Camels, DH4s, SPADs, etc. at Issoudon.
See Westermans recent post for some examples:
http://www.theaerodrome.com/forum/sh...ad.php?t=24642
Cliff