Oh, poor roo! Can you unbend his toes at all? He might be too old, but you can make a sandal out of an old credit card cut to the shape of his foot, like a soft triangle and tape his toes straight onto the piece of credit card with medical tape or bandaids. Keep him separate for a week or so and see if that helps.
Just make sure his toes are not bound too tight so as to lose ciculation.
Keep us posted!