The rifle looks like something you'd find in a Ronald Searle picture. Very, very cool all over. I'm a sucker for 18th century uniforms.
Hoof triggers, nice.
Now I would like to know how the gun works. Is it a magazine fed bolt action where you stick the magazine to the side of the rifle instead of the bottom? Mind you, those do exist though I think they're WWII era guns. Also, kudos to the bayonet setup, it reminds of the M44 series of the Mosin Nagant with a built-in bayonet. Even though the pony's rifle has a traditional blade rather than a lethally sharp flat-head screwdriver like the M44.