VERY RARE ENVELOPE FROM THE LODZ GHETTO

We know of stamps printed in the Lodz ghetto (see previous item); We have here a printed envelope from the ghetto; that is, an envelope with a stamp drawn straight onto it. The stamp shows a portrait of Rumkowski, head of the Judenrat. At the edge there is a Star of David with the word "ghetto".
Very good condition.
As far as we know, apart from this single envelope, such envelope was never seen in any sale. This is a unique item, or one of very few, that survived the ghetto! EXTREMELY RARE!