I'm building at least one horn composite for myself, if not a few of different types since I'm felling a tree to do this. But all of my information calls for green wood, generally slats about 2" wide by roughly 3/8" thick and three feet or more. I have plenty of maple and birch to use, but I'm unsure of how to cut it properly. I know how to work with it afterwards, I just need to know how to get from tree to slats.
Green maple can be bent very easily, which is the point for horn composites. It also takes hide glue very well, helping with the horn and sinew bonds. Air dried is next best, and kiln dried is pretty much right out. I want to do this right, even if it means extra work.