Weirdly enough, there are a few systems at my workplace which are in the 192.9.200.x subnet! They're only about 20 years old, though. We are actively looking to replace the entire system.
I've done work for several municipalities and police departments in western Ohio and found 192.9.200.0/24 in several. They all had a common vendor who did work back in the 90s and was the source.
