This seems to have most all the information on the questions I'm seeing posted about the money. https://en.wikipedia.org/wiki/Lodz_Ghetto_mark.
I too would like to have a copy. Please consider another print run. You should consider contacting the ANS. They may be willing to publish it under their imprint, and they now have a print on demand service too. Cal
Much of this information is incorrect. 1. The quantity of each denomination is unknown. I know where the documentation from the Lodz ghetto is. In the course of several years of research, I reviewed several thousand documents also related to the ghetto money and there was not a word about the exact amounts of denominations. 2. "and small denominations of the German Reichsmark with unique stamps indicating that this currency can only be used in the ghetto" It's a a fanciful information! 3. "The initial design of the banknotes was proposed by Wincenty Brauner," It's a a fanciful information! 4. Further coins were designed by Morduch Glazer (1890-1950). This information is not confirmed by historical documents. 5. Printing forms for coins were engraved by Pinkus Szwarc. What are printing forms for coins? Dies? Dies were made by engraver Morduch Glezer. Pinkus Szwarc was a graphic designer, painter, not metal worker. Printing forms for banknotes made by a company belonging to Roman Karol Borkenhagen, located outside the ghetto. 6. The use of other money in the Ghetto was punishable by death penalty. Seriously? Where is it written? Order No. 70 deals with heavy penalties, but not with the death penalty. This artice is full of lies. The man who wrote it had no idea about the history of money in the ghetto.
My book is available at ANS library: https://donum.numismatics.org/cgi-bin/koha/opac-detail.pl?biblionumber=200409
Do you have a photo of the fake 20 marks? Also, the 20 marks coin that I have floats on water, unllke the 10 marks coins, so it must be comprised of some light alloy. Well, another coin for the "black cabinet".
I purchased the coin pictured below from a recent CNG sale. It was done mostly to compare it to coins that I already owned that were questionable. It confirmed my suspicions that the ones I already have are fantasy pieces.
I saw that coin in the last CNG auction. It is a nice example for this type in untouched condition. The aluminum oxidizes quickly to a dull grey. Are you going to keep it as-is? I wouldn't try to clean it.