I have found four of these Fire Marshall Rings at the local grade school. The school area is around a hundred years old. I think they are from the 1940's. The other item I have no idea what it is but found in the same area as the ring.
I just scrolled down "TODAYS FINDS" to see your post where you had located another Fire Marshall ring prior to this one & I noted someone else had posted about the Ebay sightings. .
I am sorry for being repeative. . get so darn excited about an item I mostly do not think before I do. . again sorry about that