It's probably a 3-piece wheel. Look for a small lock ring that's positioned between the flange that holds the tire on, and the main part of the wheel with the lug bolt holes in it. The 18" wheels on my 59 model 3800 were made that way. There's a small tapered lock ring wedged between the full-circle flange and the rest of the wheel.
Jerry

Edit: I think I've got a wheel in the barn that's left over from that truck. I'll try to post a pic of it in a day or two. Come get it, and you can have it for a spare. I'm 7 miles north of the Alabama line near I-65.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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