Re-reading your OP I see you were asking for more than just ID.
Date of manufacture should be sometime between 1930 and 1957.
Is it a keeper? Depends. They're not uncommon but less common than the BSR skillets. There are people who want them but it's not particularly valuable. As a display piece or part of a collection, sure, nice keeper.
As a user, CI saucepans don't really have the same advantage as the skillets, the opposite actually. Enthusiasts use them for the sake of using them, but they're actually more limited and difficult to maintain than saucepans made from other materials.