I'm assuming the card is signed by him. I looked him up on Ebay to see if there were any other signed items, and the ones listed look like this one, so maybe he did sign it. In that case, it is a bit creepy that this could be the last thing he signed TTM before he passed.
Leppert (b. 1930 - d. 2021) played for the Orioles in 1955. He appeared in 40 games that season and had 8 hits, no home runs and a .114 batting average.
I mailed to Leppert on May 12, 2020, and got the card back on January 30, 2021, for a 263-day TAT. Leppert passed away at the age of 90 on January 5, 2021.
This Don Leppert is not to be confused with the other Don Leppert, who played from 1961 to 1964.