Keith, with old wood bows you have to re-teach them to bend first before you try to shoot them. Just like with a new bow, start with a slack string and gradually exercise the limbs with multiple short bends, graduating to longer and longer pulls but only to half draw or less. Then brace it low, 2" to 4" and let it rest like that for an hour or so before starting another exercising routine. All of this should take place over a few day period. Don't rush it at all.
For me, I would rather have an old bow as a wall hanger and study guide than a pile of splinters so I don't string or shoot the old bows I have. They did their work before so now it is time for their retirement and stories. Pat