I would replace the steer tires to be safe. They may look good now but once you start driving on them, they could disintegrate from age and dryness. If they look good on the inside, move them to the rear. Far less risk having them blow out back there.
Most of the tires I've found for these old trucks come from China. Not many choices anymore. Seems the US companies have given up making anything that doesn't sell in huge numbers. For the limited use these trucks will see, they may be fine. It's not like we are going to drive long distances at high speed...
For re-assembly after paint, use a plastic headed deadblow hammer to avoid damage. As has been said, if the lock ring isn't all bent from removal, it should snap back in fairly easily and be tight to the wheel. If it has gaps at the lock side, it should be discarded. I've used bent rings in the past by holding them in position with vises grips while inflating but it isn't the best scenario nor would that be kind to new paint...
