I displayed file:///C:/Program%20Files/Arbortext/Editor/docs/javadoc/aom/index.html in my browser, selected and copied the listing under "Packages" in the top left frame which resulted in (indentation added for this email listing) the following text placed in my clipboard:
which I then saved to "C:/Program Files/Arbortext/Editor/docs/javadoc/aom/package-list". Then, selecting the aom.jar in Eclipse, I assigned the directory "C:/Program Files/Arbortext/Editor/docs/javadoc/aom" and tried the Validate button. The dialog window with the following appeared: "Location is likely valid. Files 'package-list' and index.html' have been found.". The Arbortext classes within Eclipse now have attendant javadoc. Unfortunately, the org.w3c.dom ones do not... probably because of the structure of the shipped javadoc being a child in the AOM tree.
At any rate your help got me to a good level and provided me insight to this problem. Others can follow using the method I described about, or simply copy the indented packages above (remove the indentation) and save to their [EPIC_HOME]/docs/javadoc/aom directory.