Made these sideplates for my bow last year. Just got my new bow the other day, and looking for something different to make a new set. Wish I had saved a big chunk of bone from one of the bears I got this year. Need some other ideas.
There are a few more pictures here. Basically I used the stock side plates as a pattern, and used a grinder, files, sand paper to shape them. Stabilized the inside of the antler by flooding with water thin superglue. Was the first time I'd ever worked with antler, so there is probably a better way...but it worked alright for me.