Here's two duck calls that I made in the last couple days. Both are claro walnut. The first one has two accent bands of inlaid brass key machine shavings, the second has four. Both are finished with about 15 coats of CA, wet sanded and buffed. I made the second one with a delrin toneboard (delrin rod glued about 1-1/2" into the wood insert), which sounds a lot crisper and better than the walnut toneboard.
The insert on the first one is my preferred design, and doesn't incorporate a lanyard groove. The shape swoops somewhat, which effectively allows the lanyard loop to retain the insert. Using the delrin rod on the 2nd one prevents me from using the swoop and forces me to cut a shallow lanyard groove. I could make the insert thicker/wider but it would look squirrely. On future calls I may turn the 5/8" rod down to 7/16" at the part that inserts into the wood to allow me to do my preferred insert shape without exposing the delrin on the outside of the call.
Critiques and comments welcome!