SV used to fly to Tehran in the late 1960's using the DC-9 with a flight from Jeddah, this was ceased in the late 70's I think.
Service was re-installed in the late 90's (98 or 99 i think) with a single weekly flight again from Jeddah, allocating an A300-600.
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Photo © Charles Falk
I haven't heared that SV has now axed this route, and according to thier latest timetable, the flight continues. In fact, upgraded to a 747-100!
But I wouldn't be surprised if what you said Airmale turns out to be correct. (perhaps IR flights to JED are enough)