King of Parthia - Mithradates II, Gotarzes I or...?

Hi all!

I got myself a nice Chalkous and I was trying to identify the king on it. 
I'd say it's a bronze coin (15.9 mm| 1.7g).
According to the profile of the king and what I imagine would have been his nose, I reduced the range to Mithradates II and Gotarzes I.
However, from what I can read on it (with a better magnifier), I'd say that it states ΒΑΣΙΛΕΩΣ ΒΑΣΙΛΕΩΝ ΜΕΓΑΛΟΥ ΑΡΣΑΚΟΥ, which several forums associate with Mithradates II or Orodes II.
Last, a pretty similar "nose" is here associated with Orodes I(N#46920), making vacillate my initial certainty. 
Any heads up?
Thanks,
Bruno