Michel Germany does not list such "stamps". But they are listed in Michel Deutschland-Spezial volume I at the very end of the catalogue. There they also mention two books: "Gezähnte Kriegspropaganda",handbook and catalogue by Joachim Hosang and "Forged Stamps of Two World Wars" by L.N.& M.Williams,London. By the way the "Himmler Stamps" are listed in the Michel-Spezial for € 1200.- (type I) and € 400.- (type II),for mint,n.h. Exist also imperforated,from proof-sheets. No price for used ones,as all known cancelled ones,without any doubt,are cancel-forgeries. But still some people pay a lot of money to get fooled.