If you are wanting longbow limbs on a recurve riser, the pad angle will probably be different enough that the longbow limbs will have to have curve coming off the riser, so that the limb tips aren't too far to belly side at tips.
I just made a set of ILF longbow limbs for a PSE Ghost recurve ILF bow, didn't like how they turned out, expensive experiment.
Check with Bigfoot Bows...