I know you're not crazy about outside links, but really have to see this one: http://www.parthia.com/arsaces1.htm
Towards the lower half of each page they show surviving coins from the Parthian Dynasty.
They have examples of the coinage minted by EACH of the Arsacid dynasty, that you can navigate through.
The pattern is similar for all of them, a bust of the king on the front, and the obverse IN GREEK! on everyone of them.
The obverses all have imagery unique to each ruler and some of it is very provacative- and I dare say we may have made a real discovery here. If we can link some of the imagery within these coins to some of the unsolved identifications, who knows? We may be the first ones to actually see the face of ...!
You have to see these. Each regnal minting is unique and presents an actual face, and various images of kingly iconography- staffs, bows, armor, etc.
It's tempting to share some of the connections I've made, but I'll wait until you see it for yourself.
I hope this helps you.
© Charles N. Pope, US Library of Congress. All rights reserved.