Upper Silesia Scott 40 Stamp

I want to buy this stamp variety.
I need your advice for the overprint:counterfeit or genuine?Thank you.

I would make sure you can return it and send it off

Peter

A certified stamp:Auction #41 Special auction part two

https://www.stampcircuit.com/stamp-...-christoph-gärtner-gmbh-co-kg/8349301/lot-1309-deutsche-abstimmungsgebiete

Thank you peter and perf12.I think I saw a few differences from genuine overprint.
The back of the stamp don't look for the typo overprint and the bid is only 4 Euro.

The stamps website (in German) has information on this issue (scroll down towards the bottom):
https://www.stampsx.com/forum/topic...ght=&page=2&
If you can read German it's worth starting from the first page.

Thanks "Germania", but unfortunately I do not know German.
From the site recommended by you, as well as from the Michel catalog, the shape of the number 9 of 1921 is an indication for identifying the false overprint.
I noticed that in stamps 1 (your site) and 2 ( stamp I want) the loop of 9 it is oval as opposed to 3 (perf12) which is rounder.
What would be helpful for me is posting a certified stamp of a member. The auction ends in 2 days.Thank you

The website that perf12 linked to (though the link is broken in his message) seems to be a genuine example that was sold in 2018.