Here's a photo from a December 1964 press release introducing the 1965 GS. It looks like a 1" wide white wall or so. Can anyone guess the width from this photo?
John
John, using the somewhat unscientific method of expanding your photo, then finding my trusty old short metric ruler, my findings are thus.
The whitewall itself is exactly 1 centimeter wide, while the rim is exactly 14 centimeters wide. Converting those numbers back to imperial measure, and assuming the rim is 14 inches wide, the whitewall is exactly 1 inch wide.