This time the stamp is genuine. However, both, overprint and Romeko signature are fake. The genuine Romeko signature is clear and not so smudged.
The genuine overprint on these set comes generally in two types, normally in black, but red, lila and mixed inks are possible. Also, the second type exists in the variation “part of digit 3 missing”.
Here examples for the two types of overprints (those are genuine).
As you can see, it compares badly against each of the genuine types. The first digit from the second overprint type is always larger than the rest of the digits. Also, but this is just an indicator, this overprint is usually applied vertically and not horizontally.
If genuine, this would be a really rare stamp. In this case, be extremely cautions.
However, there are buyers.
EDIT: Sold for $182,50 finally.