Yes, I hear you. Deer are all the time pulling down & breaking branches on my apple trees. Hard to tell if any repairs will save the lead but you have nothing to loose by trying. Use a type of tape that will breathe - not electrical or duct tape. Something like adhesive cloth tape - like you would use to tape up a wound. I've used elastic, sticky wrap that is used by vets to hold bandages on horses. Its open weave, sticky and elastic. Handle the lead as if it were a broken bone - I have put a length of quarter round molding on the limb and wrapped with the "horse bandage" material. Looks weird - but has saved major limbs many times.
Watch the "wound" area for any signs of drying out, bacterial infection, signs of spreading infection, etc. The damaged area is an opening to further infection and if this starts, I would remove the lead. There are products that can be painted on the damaged area to help healing - check with a local gardening center.
