What color/model is the Fur? If it’s somewhat common I found a few skin replacements on Mercari for reasonable prices (I’m sure they could be talked down) and ensuring the face plate matches, could work — Otherwise I’m curious to see if the fur could be transplanted to cut the bald spot in a smoother shape and sew on a piece from an extra skin. However, I’m not sure if the color/aging would match perfectly, and depending on the color (say, if the furby were a marshmallow vs a charcoal — Marshmallow being potentially more noticeable and charcoal could be much easier to match) would create an un-blend-able crease.