Very happy to help. Below is one of the most complete guide to Mantle Holiday Inn items that I'm aware of. As you'll see from the listed items, yours is a popular pose taken of Mantle at the hotel and used in items. Your piece is interesting, and I hope you don't take my comment as a definitive statement as to whether it is genuine or not. All I can say with certainty is that it uses a common photo from the Holiday Inn. My instinct says it is not real, as I can't imagine them using this image for something other than the Holiday Inn and I can't imagine them using this for the Holiday Inn without noting "Holiday Inn" on it. If you want a more definitive answer, I'd reach out to the author of this article and he may be able to respond/answer. His personal website is hofmemories.com and I believe it lists his contact information.
http://www.sportscollectorsdigest.co...pt5.pdf?47fcf4