My grandfather's Ford step van had 16.5" rims 1n 1959- - - - -and it was a 54 model. They were direct replacements (same overall height) for 15" commercial tube type tires with 2-piece split rims. Lots of commercial vehicles were equipped with tubeless tires on tapered-bead rims back then. There were also 19.5's used on 1-ton chassis bread trucks in the 1950's instead of 18" tube type tires.
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!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!