While looking through material I got to make opinions for I found a stamp with a perfect impression of a 100 ruble HH cancel impression. I never have seen a similar perfect example. This is more rare than one would probably expect. A very beautiful item!
The material is from a dealer, so you can expect the item to appear on the market soon.
ps: Of course this is extremely valuable when checking overprints. I wish I would have such fine specimens of all the overprints.