https://www.wildabouthoudini.com/2012/05/franz-kukol-guest-book-page-on-ebay.html
WILD ABOUT HARRY: Franz Kukol guestbook page on eBay
A guestbook page signed by Houdini's assistant Franz Kukol, complete with a nice photo of Kukol that I've never seen, is currently up for auction on eBay.
wild about harryfranz kukolon ebayguestbook