William:
I don't think I'm confused....well, maybe sometimes.... I'm not sure....Anyway, I've never heard of, nor seen any evidence of anything other the Fiberglass or Steel used as tire BELTS (and I sold tires in the 70's at Harvey's Standard, which has to make me an expert....
).
Don't confuse the lack of belted Raised White Letter availability with belted red or white stripe. Both non-belted and belted red or white stripe were available. My 68 Dealer price list with an April '68 revision, clearly shows red and white stripe belted available (PW4 and PW5 I think). These same RPO numbers are listed in 69. These are FIBERGLASS belted tires, but, again, only available in late 68 and all of 69 as red or white stripe.
Calling Mr70 Rick: what RPO number is listed for 1970 belted white stripe?
Dave