For what it's worth, WW2 Chev and GMC had at least one pattern of similar looking (wood rim, stamped steel spokes, solid hub)steering wheels in 18 and 20" sizes (I think Canadian Chev and GMC DUKW respectively but I could have it backward). Some prefer the 18" even if their truck would likely have been fitted with 20" to have more belly clearance (driver, not truck), others prefer 20" for lighter steering, still others will only settle for the "correct" size and fourth group are happy to have a good old wheel in whichever size they can get.