Hans,
The SVAF reportedly had 18 MD-
315 Flamants in the mid-Fifties.
On
http://vnaf.net/ it is suggested that they (also?) operated within 312th Special Missions Squadron, but if not, then in an Escradille de Liaison.
See also
http://worldatwar.net/chandelle/v3/v3n1/frcoin.html for French COIN use of Flamants in Vietnam.
Regards,
Leendert