Could someone give me an idea of how to add some laminations of phenolic and wood. I don't know how to clamp it down with the curves. Do you folks make a jig or use some sort of inner tube?

Make a jig to keep the bow at the right angle, and leave flat spots on the piece you're clamping so you can get a straight clamping angle.

You can use your ramp cutoffs. Clamp them to the limb and it will give you a flat place to clamp to. Sandwich the overlays between the bow and the cutoffs. Does that make sense?