@ai6yr I did a map for a guy one time where the county GIS property line went through his barn. When I processed the survey he provided it turned out that his property line was about 200 feet away from the barn.
In some areas his survey indicated a fence and I could see parts of the same fence on the back parts of his property. That info let me align the survey data to the Google aerial. The client was quite relieved to see the results.