This is what works for me. First off pelt your beaver clean skinned or rough skinned. If rough skinned, flesh on your beam or whatever works for you. For me I clean skin. At one time my pelting was really clean, now with the hand fleshing tools I use it is very easy to remove a bit of meat and fat. I use a beaver/fur handling table that is the size of a beaver board, 32" x 48".
I determine what size oval it is going to be by turning the beaver sideways on the board and pulling the center on each size tightly out to the top and bottom of the oval patterns. The oval it comes to will be very close to the size ring to use. Next I turn it back to the way it is going to go on the board. Place the eyes just below the ring you are going to nail to. Nail the lips and nose out beyond the oval. Nail the two corners of the tail out past the oval. nail at center of each side, between the center and head , and between the center and tail on the oval you are going to use.
Use your hand small hand flesher to go all around the outside edge of the pelt to make sure it is clean. I then nail up one side to just about the head, then the same on the other side. Then down to just about the where the corner nails are at the tail.
You can now use your larger hand fleshing tool and remove any meat or fat left on the pelt. Lift the legs and trim them, and cut the ears out. Continue nailing around the head just ahead of the eyes.
Nail around the bottom edge, leaving those two tail corners out past your oval.
Trim the nose, lips and whiskers off just ahead of the nails. Cut the two corners off at the tail.
You can leave the ear holes open or close them with one nail. The front leg holes are nailed with two nails. do not overlap more than about 1/8 inch, or just enough for the nail to catch. Close the holes by nailing from the outside toward the center. If nailed from center to outside you will catch the skin flap when you use your beaver comb to comb the fur later.
Repeat with the rear leg holes using three nails.
The last step is to raise the pelt on the nails about 1/2 inch so there is air circulation behind the pelt and also as it dries the nails will tip in avoiding tearing. My nails are never in very tight, just tight enough to hold.
This is your finished product.
These are my tools for boarding a beaver.
Drill a hole in the top center and bottom center of your boards to hang them up. I also drill a hole each end of the beaver table and use a large spike dropped through. Then the board stays in place as you are nailing and fleshing you beaver.
So if you really want to get anal about your put up.