Hello Stig,
Thanks to the helpful Paul Badre at Aerostories :
http://www.aerostories.org/~aeroforums/forumnav/ I can now say why the two Short 8083 & 8084 do not appear in the index of Lucien Moreau's Les Aeronefs de l'Aviation Maritime. To whit they were army machines.
Using the link provided by Paul Badre
http://albindenis.free.fr/Site_escad...les_Cazaux.htm both photos I posted can be seen (in my defence they are from the same source as given by the seller, so are original). So both machines served with the Ecole de Tir Aérien at Cazaux.
Regards,
Clint