Searching for the brand brings up so many false hits, it's pretty futile looking for information about it online. The name's too generic and the phrase "winning hand" too popular. Walgreens was selling both Bicycle and their own Stud brands at the time, so I can't imagine these were high-end - Bicycle was their high-end, Studs were their affordable alternative, so Winning Hand were probably the cheap decks, stuff used for bridge games or sold to kids. Hong Kong manufacture would likely confirm this, at they weren't known for making high-end decks in that time period.