>>1104115I actually would bring the muskrat to my mom who would stew it in an old family recipe (Marylanders love their muskrat) Unfortunately I don't know that one.
As for beaver, I just roast the legs/ haunches after marinating it with some Worcestershire and a bit of Emirel's Original Essence seasoning. Roast it in the oven with a bunch of potatoes and carrots like you would a pork or beef roast. You could experiment with using some of the grease/ blood and cutting it with beef stock for an au-jus. I've cooked them over a campfire and everyone loved it, no seasoning but salt/ pepper, it's just a tasty meat.
I will try to get a hold of the old Herter's muskrat recipes for you.