This fixture was made years ago for a variety of radii. I am no longer using it but thought to give it away if it would be helpful for others. If has served faithfully for hundreds of layups and is good for hundreds more. I'm not.
You can make flat 2 dimensional curves or make curved 3-D valleys by gluing up an sacrificial upper band for stability then remove it to make your final product.
Free pick up local by two strong folks near I-95 & PA/DE state line. Contact in profile.