Mark, I know I ain't him, but as I mentioned I make a lot of similar bows: flatbows from white wood saplings.
One important difference to know is how the tree grew vs how the stave dried. For a 6 year old elm sapling, every year has been different, and there is alwaya a lot of reaction wood from wind, new growth shifting its branch load, changing shade and sun, etc. So, esp if you dry them quickly, they do tend to warp into high reflex and often lean way to one side, too. This is the result of it trying to grow straight under pressure, RESISTING various pressures. When I cut a sapling, I often leave it whole and unpeeled until I really want it, then clamp or it down to dry once I rough it out. Gives me a better starting point, but you can either steam or dry heat them straighter, later. Just more work.
The crook in his bow came with the tree. It didn't dry that way, it grew that way, and while Aksel COULD have straightened it more with heat, it's harder to do because the tree IS that way (plus he wanted to leave it). So it looks cool.