Enforcing property rights generally involves going to court (if it's civil, which the cops will usually say it is).
Deeds (in PA and elsewhere) are not government issued documents.I'm willing to bet that Amos Miller has a deed to his properties and recognizes them as valid. And expects the government to do the same. Those are government-issued documents.
They are issued by the property owner, who then hands them in to the county recorder who places a stamp on them that they have been received. The information from the deed and survey is usually stored in some kind of map to easily look information up, but the actual legal description of the property is on the deed, and that is not issued by the government.