I am familiar with these tires. They are called tubeless because they have no tube insert. They are one hollow rubber tire that are a pain to maintain. You may have seen the repair kits. They look like a box of rubber bands with a hook device to force them into a puncture after you have dipped them in vulcanizing compound. I believe I still have a tin from John Bull somewhere. Very hard to find these tires because they dry up, crack and are no longer viable. You can get repops but they are pretty expensive even by modern sew up terms. I have also seen them repoped in colors with an without tread. If you want to just show a bike you can get solid rubber replacements for a lot less but the ride is awful and unsafe.
Ray Homiski
Elizabeth, NJ