To save me buying the book, where are those six examples? You'd think there would be more than that. I seem to recall that there is one in the Bundeswehr tank museum at Munsterlager, but I may be mistaken. There is certainly a Tiger II there.
Some time ago a 'Schmalturm' or 'narrow turret' designed for the late model PzKw V Panther Mk F was found on Larkhill artillery range and quickly recovered once it was realised how rare this piece of kit was. Sadly it had been badly damaged and is now on display in Bovingdon.