We are going to  attach the leather to a backing. This can be a piece of x-ray film, or some other plastic. Apply rubber cement to the back of the leather, and to the piece of  plastic. Wet the leather again to allow it to relax. Once the cement is tacky, set the leather on the backing a push them together firmly. Then re-bevel the outline of the buffalo. This will help to stretch the leather even more, and set the leather  to the backing.