I like the cut the metal pipe at the hole and sleeve it with a radiator hose piece. A bulge at the ends would help seal.
You could JB Weld a curved steel/aluminum patch after roughing up both pieces for gaining good mechanical adhesion.
You can solder steel but you will have to study on that as a different flux and solder is needed
FWIW - I found the rusted metal heater hose pic below from a SHO when looking for Marty's hose.
Same type of degradation it appears.
