BUT, many tire makers used the black rubber for the tread cap only, and continued using the gray / white rubber for the sidewalls. This is why pre-Depression WWW tires have white sidewalls on both sides.
There are many original factory / dealer / auto show photos from the 1920's and 1930's showing these cars wearing WWW tires.
The width of the whitewall varies with the vintage of the car / tire size; generally, the witewall got narrower as the decades went by; by 1960, the white wall was down to about 1 to 1.5" inches.
If you were on the Coker web site then there is a place where they list the original size tires ( in your case you may have to look at 57 Chevy for a true comparison to our Cdn Ponchos) and the comparable radial size. Radials will ride and steer much better than conventional tires and also last longer.
Coker may seem expensive but try and buy them in Canada and then you'll know what expensive is. How close are you to the border and one of those drop places?
My car has 15 inch rims and I would like to go with approx 2" white walls.
The only thing I found so far loacally are Bf Goodrich, but they are 365$ each!!
I think I'll keep my conventional tires for this summer and try to find a better deal in the states. If you guys have contacts in QC or Ontario, please let me know.