right of publicity claims. As for the attribution in the billing block, that will not trigger rights of publicity or trademark claims. In fact, the Supreme Court has ruled that attribution is not required with public domain films. We can't say for sure whether other merchandising efforts require permission, but, assuming your permission from Price's estate covers the use (and assuming your products don't create confusion with the movie's remake), they should be fine.
P.S. One advantage of exploiting the House on Haunted Hill is that it's based on an original screenplay, not a book, and therefore you avoid the hassles that plague some other public domain films (scroll to "Subsequent History").