They look like 21" de-mountable's so probably 450x525's or 450x575's JMHO
The black rims can give the illusion of the tires being larger. That may be what we are seeing.
My guess 4.50 x 5.75 too, same on this Depot hack with the white Model A 21" wire wheels, some Model A owners like the larger tires.
They are good for a Depot hack for the extra capacity.
Lot a bit silly on a runabout IMO.
Ok I know everyone is "tire" of hearing that everything is bigger in Texas....
Well, Unfortunately we broke a few records for "biggest rain" lately.
I don't think they look silly. I have big sexy balloon tires on my speedster. They make it ride nice and help hug the road on corners.
Such tyres would be a must if the the Texan owner is a 300+ Ib "Big Boy" with an even bigger wife.