You could cut the skins into points leaving a little gap between the handle wrap and the skin. Then leave a gap, paint in a decoration in the gap, wrap fill the gap, or inlay a piece of something like bone wood or horn in the gap. Something like a little triangle, a diamond, a circle or anything that makes you happy. There's lots of choices. It's just what looks best to you. Even a fur wrap on either side of the handle wrap wouldn't look bad.
My personal preference since its in a non ending area. Would be to inlay a piece of something into the gap. Since beaver tail is black and the skins are dark, I would go with a small piece of bone or antler for a contrasting transition. Cutting te skin cleanly square or to a point. Just got slow and tedious with a chisel and it'll go fine. And keep some sandings and thin super glue handy incase it chips out a little or the hole gets a little large.
Kyle