The scan below could be of a genuine overprint, the partial postmark may be 'Senneh'?
You have been given everything you need to separate genuine from forgeries and only pick on one factor? That's not how it's done, ever. A suspicious person might think you are you just trying to get someone to do all the identification for you.
Not sure if the overprinted stamp and the portrait obliterated was specially made for the 'stamp packet trade'?
Asking for confirmation of a very bad guess using a negative conditional is being coy. This question contains an assumption so wrong that others can assume a logical explanation would probably not be found acceptable.
Based on numerous threads i'm Starting to think that it makes sense to assume all Persian singles are counterfeit until proven otherwise.
First, Scott gives you a good guide as to which issues are forged and which are not. While not absolutely complete (CTOs, worth much less for better stamps, are not explained), reprints are often explained clearly.
Second, A genuine 1kr or 2ch stamp of this issue is worth about $500 or more, probably the equivalent rarity of a US stamp worth $1500. SaborStamp is absolutely correct in being skeptical.
Third, consider that the majority of forged Iran stamps posted on SCF are likely from beginner to intermediate collections or accumulations where forgeries of better stamps ($10 up to rarities) are common. It is not optimistic to think you've bought a rarity for a song but rather bordering on delusional unless you are an absolute beginner. Consider all the intermediate collections with US classics reperfed or repaired, and with forged Washington-Franklin coils. Not a lot of difference there.
Fourth, if Iranian forgeries were a concern, you'd buy the Persiphila catalog shown or the cheaper 2002 abbreviated catalog, perhaps a better choice for the non-specialist.
I can understand the frustration but earlier US is a minefield, too.
For me personally, the expense of certification is not worth it.
Nor is it for me for stamps less than several hundred dollars in value. But you can still educate yourself on what is genuine and what is not.
Maybe its time to collect re-prints and forgeries, which I am leaning towards having read a lot of the threads relating to Persian stamps.
How can this be done if you won't bother to learn the differences between those and genuine stamps?