If you venture too far into this store, it's definitely the Land of Claustrophobia. You may be stricken with a sudden twinge of fear that you'll never get out again. However, if you're into army stuff, it's wonderland. I'm not that much into the old hats and uniforms, but their selection of steel-toe boots is unbelievable. I also couldn't help but be intrigued at all the gas masks. I was actually tempted to buy one. There are so many common, everyday uses for gas masks, after all.
Overall, If you're in Kensington, AAA's worth a look. Hey, even if you're not into anything military, you might find a nice plain army green shirt for $15 or so.