I have some of what I think is that same tan ticking. If its the same fabric, it is fairly heavy and it looks good in my opinion. I have a couple suggestions, take them with a grain of salt obviously.
1. As mentioned above by another member, if you soak the ticking in tea overnight, you will take some of the brightness out of the new fabric without really "aging" it per se. It does vary with the tea you use.
2. Although the ticking is tightly woven, relatively stiff fabric, consider lining the inside with another fabric to make it that much sturdier and stronger. Even if you plan on coating the exterior with something.
3.Consider making the interior pockets from leather, not ticking, so they will hold up better over time, even in the short term. Its amazing what one hunting season will do to a pouch in terms of wear.
4. Consider ditching the artificial sinew in favor of linen thread. It's just better stuff.
5. If you are going to make the flap from hair-on rabbit hide, consider lining the leather side with either more ticking or leather. Rabbit skin is very thin, you want a flap with a little more weight. If the flap is short a button is a good idea too I think.
Good luck, please post your pictures when finished.