I took the tires off this afternoon. Breaking the beads was quite the cuss-worthy experience. I used a Hi-Lift jack on one and the neighbor's front-end loader for the other.
The insides look really good. There's some surface rust in both of them, but a good bit of bare metal, too. The Ford logo and some other stampings near the valve stems were still visible on both. If these tires were ever filled, the tubes never leaked much.