There weren't any sets exactly as you describe, Nate. The 66 collector sets were either in cardboard cards housed in plastic pages in a blue 3-ring binder (proof like) or in red Dansco albums (full proof). The proof tokens are silver clad (not sterling). The prooflike set is in the metal of the regular issue tokens (franklinium or brsas). Also, there weren't any sets with 75 tokens. The PL set had 72.

You might be thinking of the 65 set which did have the prooflike tokens in a blue binder with plastic slides. There were 27 tokens in this set.

As Jerry mentioned, these sell for low price-per-token in the set, maybe $1-2 if sold to a dealer, and date doesn't make much difference. There are some tokens that go for a premium due to popularity of the casino name e.g.,Sands and Landmark.

The last year for FM collector sets was 1969, which was the end of production for the first era of private gaming tokens. When production resumed in 1979, Franklin Mint had competition from other, lower cost mints, and didn't get all the business as they had in early years. They continued to produce for a few casinos into the 1980's, and are now out of the gaming token business.