Paris is chock full of charming and unusual shops that might take a bit of looking but are well worth the effort. Several years ago, I bought *Paris Made By Hand, a treasure of a handbook featuring Paris' most unusual shops by arrondissement. It took some searching but Peter and Mary helped me find it. Tombées du camion, which means "fell off the truck" is a tiny shop full of an electic mix of unusual finds. This is a place that although hard to explain, is a photographer's paradise.
Tombées du camion
17 rue Joseph de Maistre
* Of note: I recommend doing a search online for any shops you might want to visit as I've found that since the book was written, several have closed.