Come now...the ancient Greeks were technologically advanced enough to have a medium for writing that didn’t require them to haul around two ton stone calendars. Clay tablets were in use thousands of years before the Greeks.
The “Olympic calendar” hypothesis isn’t holding up to simple logic.
It was designed to be portable.
It's no more complex than clocks of the 14th or 15th century.
BTW, in the period when the machine was built the Romans (and their satrapies) did not yet use a leap year in their calender, and unless you account for the 1/4 year drift each year you end up with your calendar out of synch. The machine accounted for that 1/4 year problem.