Yes, you are correct. But the office is 'dioiketes' with an extra i after O. I think it is also on the seal, but you can't read it because of the off centre strike. A dioiketes was indeed a fiscal official. Usually, a
provincial area of authority is mentioned on
seals (like 'dioiketes of Sicily' for example), but as your seal show, these officials did always feel the need to specify their office further.
Regards
Gert