There's definitely non-fake signs in
Gordon. The article refers to Rushville, which also has at least one sign (screenshot of similar article from the same local paper preserved on the the Historic US20 website). GMSV is 2012, so doesn't show these more recent additions. I might have put the ends a waypoint too far, but there is decent evidence that Historic US20 is signed along US20 at these two towns.
I'm fine with routes, especially US20 ones, being removed if there's no evidence of them.
IIRC, the Historic US20 site used to have a map with cities with signs marked on it (hence Sandhills, NE, etc). These signs could have just been someone putting it up on their wall, rather than being used on the road.