I bought some lots on Delcampe that I thought looked promising. One item is this block of four.
What do you think? I was in a hurry and made a bet, looking forward to study the cancel. After receiving and washing the item I made this scan.
I did not like what I saw anymore. The dark black cancel fragment at the bottom looks fake and the ink of the overprints is looking odd. The gray cancel is not readable.
I high resolution scan (2400 dpi) provided more insight.
This definitely looks wrong. I think this is a digital copy of an overprint. Compare the four overprints. They look absolutely identical. I guess I need to check more carefully before I bet.