This may give you a chuckle, but the exterior hinges are actually commercial
refrigerator hinges and are still available from a number of places.
It's the Kason Hinge, part # 139, flush mount. It is available from many online stores and from Team
Trillium. The Kason #139 is a specific shape that fits the door molding for older Trilliums.
Here's one quick source... Google is your friend:
Cold Supply, you'll see the picture of the hinge about half-way down the page.