Dating 1960's Thorp (Wilson) NFL Game Ball

[Bhawk2]

I just got what is purported to be an NFL game ball. It has a notation of the date and score of the Vikings - 49ers game on September 17, 1967. It looks right - it's a Wilson Thorp ball with the Pete Rozelle signature and "THE DUKE" on the other side. I'm not sure what date code would be right for 1967. I think it would be JJ, but I'm sure someone will know that.

Unfortunately, the date codes are very hard to make out, but it looks like DD to me. Can anyone verify what the code would be for 1967, and 1966 since this was the first game of the season?

Thanks

[RaiderNationPDX]

1968 was the first year of date codes, if I'm not mistaken (AA). 1967 shouldn't have any code.

The written-on date may be your best bet of dating it inside the 1960-67 window. 1960 was the first year of the Rozelle Dukes, 1968 would be AA, 1969 would be BB, so anything from 1960-67 wouldn't be attributable to a specific year.

I trust any fellow collectors will correct me if I'm wrong, but I believe this is a fairly accurate guideline.

[RaiderNationPDX]

The part I forgot to add was the Duke balls were phased out in 1970, so the only two years of Duke with date codes were 68 and 69.