What symbol appeared on Paladin's business card on the U.S. TV western "Have Gun, Will Travel"?

The show "Have Gun, Will Travel" was an American Western CBS television series that aired on U.S. television from 1957 through 1963. The star, Paladin, was a professional gunfighter and West Point graduate. After the U.S. Civil War, he settled into San Francisco's Hotel Carlton were he awaited responses to his business card: over the picture of a chess knight "Have Gun, Will Travel ... Wire Paladin, San Francisco."

Paladin usually presented his business card by taking it from his waistline (usually under his gun belt or out of his pants). The card was, understandably, wrinkled or bent when presented. However, when it was shown on the TV screen in a close-up, it was usually a new flat card with no wrinkles or folds. Next, when the card is in Paladin's or another person's hand, it is once more wrinkled. Notwithstanding all of these actions, the message on the card was very clear!