Glock apparently sold Iran 30,000 Glocks in 2007- https://www.steyrclub.com/threads/glock-sells-30-000-pistols-to-iran.2029/
This image is from last year's IPAS 2016, along with numerous Glock brochures from there as well. They don't have anything about its origins, just straight spec sheets in Farsi. http://so-l.ru/news/y/2016_10_28_oruzhie_i_sredstva_individualnoy_zashiti
Then there is this dude, an IRGC guy from the Basji unit, with what looks to be doing a mag dump from a modified Glock 19, notice the modified rear slide plate
Curious indeed...