depence on where its leaking from head gasket engine will be scrap from radiator it may be fine as long as u dont over heat it to much and warp the head. im gessing its the radiator the rust could be from a nackard radiator i recommend u take it to a local garage and get then to diagnose the fault . if fit a new radiator make sure u bleed the cooling system otherwise it will over heat and probly wreck ur engine
Bradley
January 2009