I had in fact read the rules,
read them again :-P
The reason I was unsure was a question was ask of the Dwarf Rings all being out at one time because of them being unique and the center area of the card all saying Artifact: Ring Even tho each ring was called something different. The answer was that yes all could be out as long as they were out on 4 different dwarfs.
You are mixing two different things: Item Class and Card Title.
All Dwarven Rings have different Card titeles, are unique, are Artifacts (not Conditions, so are another card Type and have other rules!) and have a Class of Ring.
Item Class:
Each character may bear one possession or artifact of each class at one time.
Some possessions and artifacts do not have a class. There is no limit to the number of cards without a class that a character may bear.
The Saga of Elendil is a Condition.
Conditions have no Class. You can have up to 4 copies in play. You can play up to 4 copies on the same companion. Thats where the Unique comes into play. If your card is unique you can have only one copy of your card in play at the same time.
so:
You can play 4 copies on
Endurance of Dwarves on Gimli but only one copy of
The Saga of Elendil on Isildur.