Because people were asking, I think this video was the most helpful over all.
https://www.youtube.com/watch?v=A54xUpM8bUI&t=1328s
I basically used the same shape from streamline stock that was already on the airgun, and I mostly just did things by eye because I was ok with the stock not being perfect or even perfectly symmetrical.
Gorgeous work! I wish the Osage Orange would Keep that yellow, the first time saw it I thought that it had been dyed.