That would be me, then?
The Shades of the Harz layout, was only exhibited six times (to my knowledge). Twice, at the big Warley Model Rail show, NEC near Birmingham.
The owner had passed away, and a passing comment at the end of the show, sent me in search of information.
Long story short. I was able to offer the layout a permanent home, care-of the Chasewater Railway. The layout came to us their, and we then had to make it fit, in the long 'loft' we had available.
We were 'gifted' the layout, and a LGB - mad friend, bought a large quantity of the original stock.
The layout is open Sundays, most bank Holidays, and gala days.
A core of 4-6 have done this voluntarily, since we got to a stage to let the public in..