The approach I chose to go with for the gif links (join, drop, admin etc.) was to retain the gifs for the en_US version but let other locales simply use texts instead.
This way the en_US version can continue to enjoy the pretty gifs inherited from SloanSpace (they can be changed of course if the look-and-feel requirements are very different) while people can still have the labels of the links in their locale of preference.
Hope people find this compromise acceptable. Kudos to Jeff Davis for suggesting this solution.
