Drain the tank and use a borrowed battery.
If you get it running use the sea foam one can go about 8 gallons. IF it starts and runs you will need to replace the fuel filter after it runs a few hours, maybe before it starts.
Again if you get it running count on replacing all water hoses, belts and tires. Change the oils and coolant, and then check all vacuumed hoses and rubber boots.
Hopefully the rodents haven’t made it their home and eaten the wiring.
If you get it running use the sea foam one can go about 8 gallons. IF it starts and runs you will need to replace the fuel filter after it runs a few hours, maybe before it starts.
Again if you get it running count on replacing all water hoses, belts and tires. Change the oils and coolant, and then check all vacuumed hoses and rubber boots.
Hopefully the rodents haven’t made it their home and eaten the wiring.