You've picked a great board! Perfectly straight grained. For a traditional bow, selecting decent wood is already half the battle.
The design you've chosen a very difficult design, especially for a beginner, but even for an experienced bowyer. This lay-out is called a Mollegabet and not a true longbow per se. It depends on the definitions though, as some people would call any bow where the string only touches the string grooves a longbow.
A Mollegabet (sometimes abbreviated to molly on here) is notorious for the width transitions from handle to limb, and from limb to lever. These abrupt transitions can easily be weakened if the bowyer does not compensate with enough additional thickness. Bend creeping into the transitions often leads to a fatal crack. Given the limited thickness of this board (only 3/4" true thickness), you're making it difficult for yourself. You should glue on an additional riser, but that is likely to pop off. Use several very thin (about 1/8") laminations and glue them onto the handle and fade area. I would also recommend narrowing the handle and bending limb area. The handle can easily be 1" wide (but glue on the riser pieces first). The bending limb is now a uniform 2" wide. It is easier and better looking to taper it slightly. Say from 2" near the handle to 1½" at the end near the lever transition.
Good luck and keep updating this topic!
