The cart looked a lot worse than the picture shows. This photo was taken for the ad, so kind of hid the cart with the flat tires behind the tiller.
Started off by removing the wheels, they were rusted fast to the axle. While I couldn't get the tubeless tires to hold air, figured if they could be removed without damaging the bead, might be able to insert tubes. So after removing them, sand blasted and painted the rims, then ordered a pair of tubes on ebay. After the tires and tubes were on the rims, figured it was worth it to work on the cart. So spent the next several days sand blasting the rusty areas and sanding the faded paint, then primered the cart. The steel tube that they used for the tongue had split where it was flattened to meet the axle. Not sure if it came that way, but wound up welding it anyway. Three cans of Rust-Oleum blue later, it looked good as new.
The cart now looks great, almost don't want to sell it. But given that it hadn't moved in over twenty years, well maybe it's not needed so much anymore.
Update: Sold the cart. It's always a little amazing when someone buys something that others consider junk. It just goes to show the value of a little spray paint.