Mog-620. Wt = 20.51g. Date not quite clear
Stevens Collection

Wt = 20.77g. Bahman
Stevens Collection

Wt = 20.55g. Diam = 19.2mm. Shahrewar
Photo from Zeno posted by xpoleg

Aban Wt = 20.40g. Diam = ~20mm
Photo from Zeno posted by Lingen

Diam = ~21mm. Isfandarmuz
Photo from Zeno posted by Mervin