I have a 1957 book of cartoons called Dear Patient. It was a collection of cartoons given to doctors for their waiting rooms by the Schering Corporation.
As far as I can tell it's copyright was never renewed. I checked online under it's name (some similar named books, but the info didn't match this), the editor Austin Smith (I even tried Auston Smith in case of a typo) and both the publisher Physicians Publications and distributor Schering Corporation, but it didn't come up.
So if it is in the Public Domain would the DCM be interested in a scan of it?