So you are looking for preserved aircraft in the triangle Hyeres/Orange/Istres?
Next to the airport of Marseille is village Saint Victoret with a small museum on government agencies aircraft:
Two are displayed outside:
More is preserved inside the building, like a S-2 Tracker, an CM.170, Mirage 3, MS760 etc.
Another village near Marseille airport is Vitrolles, it has a school which has a Mirage 3 outside. Inside a CM.170, Broussard and a Corvette are believed to be present.
In the industrial estate of Orange village a museum is situated (
http://www.musee-a5e.com" onclick="window.open(this.href);return false;) and is open weekdays between 10-12.00 and 14-17.00hrs LT. But all, except a two orso, can be seen from outside very easy. GPS coordinates are 44° 07.454'N, 4° 50.283E
Check out Cuers dump on the Factory side, and also the aeroclub, for some preserved/dumped goodies.
When in the area, you might want to visit the museum of Montélimar (
http://www.meacmtl.com" onclick="window.open(this.href);return false;) and Valence (CM.175 along A7/E15, exit 15) and some choppers and a Broussard at the airfield. Both a bit more north then Orange, but worth the trip.
Since last year Salon de Provence has two (red/white c/s) Tucano's preserved near the maingate, they are both visible from the housing area. Some say they are part of the firedump.
There is some more w&r around this part of France, but it's a good start to begin with on this topic.