Rick,
You are corrrect about the cross wedge. I believe it would take as much time if not more to make the pieces, slot the arm, and then get them to fit- than it took to do the forearm , arm hanger and the screw attachment combined.
I just would not undertake to make the forearm with a wedge. I didn't do it for mine, nor for Jim's.
As my Mother used to say : "too much sugar for a nickle".
Here are picts of my carbine, Jim did the stock checkering and finishing on it too. I used the screw in the forearm as mentioned above.
