The mintmark is below the denomination on each coin in both sets, in the form of a monogram ЛМД or ММД (for, respectively, Leningradskiy / Moskovskiy Monetny Dvor). The pictures above are too small to see which; even with the coins in front of me I generally need a magnifying glass to tell which is which.
As to whether the sets are genuine and from 1991/2, I can't see that anyone would have the slightest interest in counterfeiting the coins. They are all available at low cost. So I suspect the coins are real. Whether the packaging actually dates from 1991/2 or whether some enterprising individual has printed new ones and inserted genuine coins, I can't say.
