Card game:Cards for Finding the Name and Age of any Gentleman

A set of "Age Cards" were advertised in the McLoughlin Bros. 1875 catalog of children's printed books and toys. The catalog entry reads: "one hundred and twenty-seven names are enumerated upon the cards. By a very simple method the name and age of any person can be ascertained." There are eight cards in the small slipcase, printed with numbers and names. How the trick worked is a mystery. Also, the case is marked for "Gentleman" but the cards within have ladies' names. Was there a mistake in packing this deck, or have the cards been switched sometime since 1875?