I'd love my '28 A special coupe to be all original. But it isn't. Maybe someday. Until then I'll go with what appeals to me rather that what was original. The whitewalls on my coupe (in my opinion) make it look dressy. They go with the chrome radiator shell, light bar and headlights. It also has black wheels, so the whitewalls dress up the wheels a bit. If it had wheels of some accent color, say creme, or red, I wouldn't want white wall tires then either.
My pickup is a different story with a two-tone paint job and a little pin striping, it's dressy enough. No need for chrome, or white walls on what I see as my work truck. When Dad's 28 PU is restored, it'll be blackwalls, and black wheels for the same reason.
BTW, a thread like this is refreshing to me every once in a while. Gives guys a chance to post pics of their cars. I never get tire of admiring your Model A's, gentlemen.