You can stack a whole handle with thin pieces of horn and screw on a buttcap then shape,just like a leather stacked handle.They look really cool also.As I said no horn should be left in a junk pile,neither should any small thin scraps of ivory or wood or antler,it all still makes great handles,just use your imagination.
Good Luck on your search for American bison (Buffalo) and when you get some use it with pride,and yes it will make a great handle (you may have to back fill it but that is ok)
Bruce