There are hinge makers that make real narrow hinges. For instance, Lee
Valley (www.leevalley.com) has some 100 degree lid stays and several knife
hinge designs that you might be interested in. These are the only real
narrow hinges that I found when looking quickly. The ones in the catalog
are solid brass and might be a little pricey for what you are interested in
but this is a start.

Of more interest might be some plastic hinges such as offered by Reid
(www.reidsupply.com). They have a variety of sizes and colors of continuous
plastic hinges made of polyolefin that you could cut to your requirements.
Make sure that you look at the physical properties of polyolefin. They also
have some Acrylic Hinge with a Flex-Fold Hinge that looks interesting. The
sides are acrylic and the hinge, a separate part, is a urethane esastomer
with both being extruded together.

Roger