Very nice, you are not almost there but made it a long way. The next step (certainly not the last) is to see and accept that without government the concept of private property changes so dramatically that one could argue it not to exist anymore.
Before you get upset over such an absurd looking statement we should examine how this property right or any other right is to be enforced without government. It seems a pretty lame idea to fill the gap by gathering a bunch of experts and quickly build something that smells looks and tastes like government just to enforce property rights.
Slaves you said and you are right. The true colors are revealed when part of a country wants to split off. Humans are owned like things. Their owner is not even a person. I would argue it a life form but thats a different story.
As some other formula is not just possible we have examples of it plastered all over history. So what happened with all of those civil constructs? It seems fair to say they were all eventually matched against well oiled war machines send there by governing entities or formulas.
They came specifically to enforce their idea of property.
Its like employee owned companies. On paper these would be the ideal employers. In reality we hardly see any because people rather argue than get their shit together. It becomes a blunt instrument. Not because the formula can't work but because people simply aren't enlightened enough to run such things.
So keep at it, you are on the right track. I don't claim to have answers but I'm sure as hell trying to ask the right questions. I'm not almost there in that.