[GasHouseGang]

I've never seen anything like it, but since Musial was the spokesman for Red Heart that would make sense. As Sports Collectors Daily said about the 1954 Red Heart set:

"The checklist includes Mickey Mantle, Warren Spahn, Duke Snider, Ralph Kiner, Nellie Fox, Billy Martin, Ted Kluzewski, Richie Ashburn and some guy named Musial, who wasn’t in either bubble gum set that year, having refused to sign for what Topps and Bowman offered players. Musial, in fact, was the advertising spokesman for the set. Getting him had to be a major coup for the Morrell/Red Heart people and a face palming moment for the gum executives who couldn’t afford him."

I can imagine the Red Heart executive may have wanted an in-store display that included the Musial card since he was an exclusive spokesman. Someone could have removed the card from the store display since it would have been quite large. There appears to be remnants of an adhesive on the card back like it was removed from some backing. The attached photo was a display they used to sell the set. It was two Red Heart labels and 10 cents.