These's a shop in the 6eme, maybe on Bd. St Germain, called Odeon. Good service, Leica dealer. Check 'em out.
You beat me to it, it is on St. Germain, not far from Metro Odeon, where two lines metro lines converge. They used to have two shops, connected, one for new and one for used. Very nice people, they cleaned out my Nikon once for me after I dropped it in some sand.
No charge.
It is Odeon Photo, it is on the side of the street toward the River, North? Across from the movies, toward the post office. They used to have a good stock of MF and 35mm films.
I used to stay near Place Odeon, at Grand Hotel del Balcons, I hear Alexander is still at the desk, if you wander by, ask if he still has the Nikkormat I brought him. ;-) It is a 3* hotel at a 2* price, charming place, on Casimir De La Vigne, No. 3.
You might find some photos at the street markets near by, the Pont Neuf is very close.
You will be treated well.
FNAC is a chain, you might find one in a number of locations, a friend worked at one near Chatelet.
Regards, John