//edit// Some of your links just show that some people lived on that bit of land. I think you need more to claim a country.
Bear in mind passports are only relatively recent objects.
Also worth pointing out the British tried that "I think you need something more" line with Terra Nullius .. and their own legal system ditched that as rubbish:
https://australian.museum/learn/first-nations/unsettled/reco...
Not having anyone say you're a different country, aka sovereignty.
These countries:
https://mgnsw.org.au/wp-content/uploads/2019/01/map_col_high...
remained sovereign for tens of thousands of years.
Whereas, for example, the "United Kingdom" as a country (of four kingdoms) only dates back to 1801, prior to which there was a long history of contested sovereignty claims, there's some interesting paperwork declaring a King of Scotland as a the King of England, etc.
Do you have a definition of what makes a country yet?
This question of oldest country that you've laid claim to does rather rest on something that works about the globe so that we can compare.
The "definition" (as such) provided by 'relaxing' fails England as England has been claimed by a Scottish King to be his realm.
I'm with you though, I reject that definition.
You might as well say France only dates from 1945 if we follow your logic.
How do you define country? Continuous occupation and law?
I remember talking to David M as a kid about the works he kept touched up and the stories that went with them.
https://www.magabala.com/products/yorro-yorro
https://pursuit.unimelb.edu.au/articles/australia-s-oldest-k...
https://www.nature.com/articles/nature21416