Sounds like you have quite a bit on hand.
The only thing I could suggest is putting in inventory sheets in the top of each box....listing the amount, date of purchase (and date of manufacture if available for surplus) and the price per round.
That makes it easier to rotate stock. These are things I wish I had started doing years ago....I still have some Wolf I bought on 9-11-01 lingering around in bandoleers and magazines. Keeping that stuff though, brings down my average price per round since it was 9 cents per round vs. 25-30 cents per round today. (at least 'normal' days)
I also save every desiccant pack I get from jerkey or medication and toss them in to random boxes. Humidity an temperature really aren't much to worry about in Montana though.
I recently started converting dollars into silver, I am trying to do similar things each time I invest. Price per 'round', premium paid...etc. It is a very similar situation... boxes of various types, amounts, and prices that you need to keep track of. Things that, should you ever need to sell (or shoot) you know whether you are screwing yourself over or not.