I have about 5 ounces of whitetail back tendons I'm willing to trade. These are not whole tendons, they are long strips of tendon with the shorter fibers removed (I use the shorter sections to make sinew glue). All individual tendons are over 12 inches long, many are over 15 inches and some push 20 inches. These are very clean; I scrape the meat, fat and membrane off both sides of each back tendon, then soak them in several changes of warm water before I air dry them on a large baking sheet. To give you a sense, it usually takes 5-10 individual tendons to make an ounce.
I'd love to get a nice quiver, some hunting-quality stone arrowheads, turkey or goose feathers, or other things. PM me if you're interested.