The older Cessna's don't have a green arc - they might well have a red line although I've never been consciously aware of it.
Perhaps you should be aware of it. In any aircraft with a fixed-pitch prop it's very easy to exceed redline by failing to reduce power in a shallow descent. Just as pulling too much G can cause permanent damage that later kills someone, overspeeding can cause damage that later results in engine failure or the catastrophic loss of part or all of a prop blade. (In some, the V-tail Bonanza for example, you can get the opposite problem, a shallow dive with cruise power can make you exceed Vne and pull the tail off.)
You make an assumption that RPM = Power setting for a given aircraft type, which is not a good idea. For a given power output, all other conditions being equal, RPM will vary according to the prop fitted (and of course its condition).
The prop is every bit as much of an airfoil as the wings.
(edited for peer spolling)