I think the longest recurve limb form that Bingham has plans for is a 68”, and can be adjusted to 66 and 64. It uses a 21” riser and builds a very nice bow, from the ones I’ve seen.You might try checking with Kirk at Bigfoot, I seem to recall he is now building a 21” riser, with his new “Bare Limbs”, that might get you into the right length.