While the cancel looks nice and clean (it is fake too) the 100r HH ruble overprint is a very crude forgery.
When I check the 100r HH overprint the first thing to look at is the base line of the “100r” part of the overprint. The genuine overprint always shows a raised second “0”. You can easily detect 80-90% of all the 100r forgeries with this. Of course there are more errors. The zeros are not tilted, the foot of the “1” is wrong and the shape of the “r” is also wrong. But fake is fake, there is no need to go into more detail once you find the first error.
For more information see my article about the 100r HH overprint in this blog.
Besides this, the lilac “Z” overprint beneath the 100r HH actually looks good. A pity the forger destroyed this nice stamp.
It looks clean and nice. Only detailed inspection shows it is a dangerous forgery. The characters “ERIVAN” are to narrow, the line of the date is not even (it goes up to the right side) and the dot between month and year is missing. Not easy to see if you cant compare directly with a genuine one. I got another card with this fake cancel and a single stamp (charity issue) with an identical 100r HH fake overprint and this fake cancel. I think there are also differences in the upper hook of the serial character compared to the genuine cancel, but I need a better scan or the item itself to really check this.
The description of the auction lot mentions a Holcombe certificate. This is either fake too or another case of the “universal experts” entering terrain there are not really familiar with.