I know this an older post, but I have some info to add.
The first image is from http://www.dhm.de/magazine/orden/abbs/002.htm Kat.-Nr.2 in the Deutsches Historisches Museum.
The Wilhelm-Orden was featured on the cover of Orden-Militaria-Magazin in 1996 which I picked up several years ago. Unfortunately, I do not read or speak german and connot read the article. I would be very interested in anyone who could translate the article. But there is a 15 page article with b/w photos of cloesups and a detailed write-up on the order. Included is information about the design and manufacture of the award, as well as a list of 15 recipients, and many other details. This thread suggests that there may have been as many as 63 awarded. Still a very rare item indeed.
What type of value would such an item command today?
From WikiPedia:
"
The Wilhelm-Orden (English "William-Order") was instituted on the 18th January 1896 by the Emperor of Germany and King of Prussia William II, and was dedicated to the memory of his grandfather Emperor William I "the Great". Like the civil class of Pour le Mérite, the Wilhelm-Orden was intended as a high award for service to science and the arts.
The insignia of the Order consisted of a golden medal with the portrait of William I, surrounded by a golden wreath and suspended from a heavy golden collar. This collar with a weight of 222 grams bore the words WIRKE IM ANDENKEN AN KAISER WILHELM DEN GROSSEN (English: "Work in the memory of Emperor William the Great") and was designed by the jewellers Emil Weigand en Otto Schultz.
The order was very exclusive. One of the first to be decorated was Otto von Bismarck. Also among the recipients was physician and Nobel laureate Robert Koch."
