Firestone Wide Oval's Original VS repro tread count?

[firstgenaddict]

There was a 71 LS6 Corvette at the National show this week and it had the Original FIRESTONE F70 15 Wide Ovals which have a 9 rib tread pattern whereas the COKER reproductions have a 7 rib tread pattern. (For which the NCRS does a 30% deduction for tires.)
My question is does anyone know if this pattern extends to the F70 14 Wide Oval used on Chevelles, Camaros, and Novas?

[67since67]

Three Firestone F-70x14s. The original '67 on the right and the well-worn '68 in the center, tread and dimensions are the same, differ only in the sidewall. Both are nine rib tread. The repro on the left has seven rib tread and is about 1/2" taller.