I have just acquired a 1978 Mercury Electric 20 hp that has been setting for a long time. All of the steering and Throttle cables are rusted and severed into. The motor has good compression and spark that I can tell by pullin the cable on the flywheel. Can I change motor to a pull start motor and steering handle? Or would it be cheaper to leave it alone and stay with what it came with. All of the wiring harness is bad also. Any help would be greatly appreciated.