Here is the fully modeled muzzle! I've added all the hardware and loose ends, but haven't really textured yet.
I'm thinking of putting the ARC logo directly over the feeding port, you'l look extra-gagged while wearing it.

The set of buckles at the back doesn't always have to be separate, it can remain buckled to the top-of-head strap to keep the whole thing together.
Model is shown here without the plug.

Attached on my Patreon is an animation showing the internals of the built-in gag as well as an animation showing the inside of the muzzle unfolding to show the whole gag!
I also downscaled the animation and posted as a gif here: https://www.furaffinity.net/view/36473361/

This should be easily adaptable to MOST other species. I need to make a different one for Humans, but the strap layout here should work for most animals that have any kind of snout. Even birds with beaks, it just means pushing the straps and buckles around.


Special thanks to  Petruz for making his furry models freely available, and for giving me his approval to use them!

Full size version and animations available to all patrons on Patreon here:
https://www.patreon.com/posts/37202701
(open the attachment below the description to view videos)