If you trailer the car, keep the originals on it if they hold air and aren't weather checked. If you drive it, you'll just have to take the point hit and install as close to the same as the car came with as possible. That would be a 225/70VRx15 Goodyear Eagle. You wouldn't want to be caught at a show with lower speed rated tires than the car came with. Some judges might let a higher speed rating slide and some may not.
As for the battery, good luck. You may have some luck at a swap meet such as Fords at Carlisle or Columbus, Ohio spring or fall all Ford swap meet. You might try salvage yards. Sometimes one will be left in a wrecked car intact. Sometimes they may have a bunch of battery cores and you might get lucky and find one there. But it's getting more difficult all the time with the EPA requirements.