I wonder if his story is legit but he is confused in assuming your machine was his fathers. I think there are 3 Wizards for sale in the Wisconsin area on Craigslist currently.

The owner of The House on the Rock is/was a friend of my uncles and fathers. The obituary is from the same area as the museum. They have many antique music machines. The area code is correct for Wi.

Anyway not sure how he'd be able to prove it was the same machine outside a serial number. Even if he did he'd have any recourse. Just sounds like an unfortunate coincidence (potentially).