Go to your character view ("c") and click on the backpack icon in the top right corner. Roll over the piece of gear you want to unhide, and click on the blank slot (the first one). Voila!
Just as an FYI, when you roll over the gear icon in the magic wardrobe, the blank space reverts back to the armor you have on, the red "no" symbol hides that piece of gear (same as unchecking it used to), and the rest are costume pieces that are currently in your magic wardrobe.
Terenth P/K/M
Darkorchid Wd/R/W
And a K/M/S, P/W/M, D/R/S, W/R, R/S, M/Ch and innumerable level-one alts.