Beardbuster, a Google search on "wing bone call making" will get you lots of info, including this from the NWTF
http://www.nwtf.org/tips_adventures/tips.php?id=287Supposedly hen or jake wings are better for calls than mature gobbler wings. You can make a 3-bone call as shown in Barry's pic above using humerus, radius, and ulna or a 2-bone call using just the two smallest bones, the radius and ulna. After a friend gave me a 3-bone call he had made I made a couple myself. It is not particularly difficult to do. I find it hard to make a good yelp consistently, but I have gotten a gobble in response to it when everything was being ignored. Frankly, I think it may have been a shock gobble. Mine makes a high-pitched, penetrating yelp but I seldom use it unless everything else is not working, although I always have it in my vest.
Making a wing bone call is definitely an enjoyable little project to help kill those interminable 47 weeks between spring seasons.