66" and a 29" draw is somewhat of a challenge but certainly one that you can do. If you went for a bendy handle bow it would be easy.
Looks like the outer wood has a nice dark orange color indicative of a decent summer/spring growth ratio. The stuff in the middle doesn't look so hot (light yellow, lots of spongey spring wood). You don't want that for your belly. I would lay the bow out along the left side (the thicker side) and go a full 1.5" wide if possible. For a 29" draw that will make your limb fairly thin, I think you will stay within the good orange wood that way. That is important, if your belly winds up in that spongy yellow wood you are going to see a lot of set when you tiller the bow.
The wood on the inner part of the limb looks good too. You might consider splitting like Pappy suggested, and planning on gluing on a handle piece to make the needed weight. It would be chancey though.
The fact that the growth rings are so thin, would make me lean towards using sinew on the back. Not a heavy layer, just a thin layer for protection. then you don't have to stress over chasing a ring. I would certainly just remove the sapwood and not get down into the orange too far, because you only have less than 2cm and you need most of this so your belly wood still falls within this better wood as stated above.
