Interesting spelling of “Ancient of Days” in the upper picture.
I wonder it that was a transitional stage (ο παλεο [των] ηεμερων) between ancient Greek (ο παλαιος των ημερων) and modern Greek (το παλαιο των ημερων)
The icon does look old but not ancient. Maybe it was some Serb attempting to write in Greek! Who else would leave out artciles! :)