Thanks Grigg.
A disadvantage to being here in New England is the lack of big old farm trucks. Small New England farms and our roads meant that there were never very many Grain trucks and most junk yards sent that stuff to the scrapper long ago.
Looks like made to order wheels are going to be the answer. At least I know all 6 will fit correctly and be straight and no rust.
Wheels Now will do them (22.5 x 6.75) with correct center and bolt pattern for $410