I have wondered if you could simply weld the split rim onto the rim. -But again, I just don't think it's necessary.
Yes, you could weld them together,
No, it is not a good idea, not at all.
You would have to weld them together with a tire and tube in place, and throw away the rim when you either had a flat or wore out the tire, you could cut the tire off, but no way to get a new one on.
Not to mention the possibility of weakening the rim by welding it, asking for a future crack and failure.
I see you read the tech tip, and as far as I know there are no other other options out there to get tubeless wheels on the AD trucks.
Well, I take that back, I just picked up a set of Dayton wheel adapters for my truck, and I can run 22.5" Dayton rims with them, but I don't see that as an option worth searching for, as I seriously doubt I ever see another set of those 10 lug Dayton wheel adapters. They do have 4.75" center hole, so they would be the only truly bolt on, no fabrication or machining needed, way of getting one piece wheels on a pre 54 AD truck.
If you are dead set on one piece wheels it's either the easy to find 19.5" wheels, or the harder to find 22.5 wheels and turn a set of bushing to adapt the center hole. Or swap axles to 54 model with the 5.25" hub.
Grigg