Steyr HS 50 in Iran, Counterfeit?

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Take a look at the two photo below. The first is the original Steyr HS .50 AM, and the second is the newer M1 version.
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Steyr HS 50 (European & USA model)
Steyr HS .50 M1 (European model)
This is a frame from the video I posted earlier this week showing Iranians using the Steyr HS 50.
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At first glance they look the same. Looking closely, there are some significant differences. The Iran version lacks the barrel taper and barrel fluting. The Iran model has uses an unknown pistol grip, not an M16A2 pistol grip. The trigger guard on the original HS is straight, on the Iran version is not quite straight, it has a slight curve. The Iran version also lacks the Steyr markings forward of the chamber.
Has Iran been cloning the Steyr HS 50? Iran does not make repeat purchases of any weapon that can be cloned (which is everything short of the Russian S300 surface to air missile system). They even clone clones, notably their clone of the Chinese CQ, itself a clone of the M4!
A reader emailed me this photo, said to have been taken in Iraq. I initially dismissed the rifle as a counterfeit because of the number of differences to the Steyr HS.
Then I watched the Iranian video again and noticed the Iranian version did not match the original Steyr. This Iraqi version has a two buffer muzzle brake instead of the Steyr original three buffer (also present in the Iranian version), and appears to have a rusted bolt screwed into the rifle’s bolt where the bolt handle is supposed to be, it has the same pistol grip, plain barrel and trigger guard curvature as the Iranian version.
So I wonder, did Iran clone the Steyr HS 50, as they were bound to do eventually, or did Steyr sell them a customized version?