When all else fails, taste them. Put each different grain in your mouth individually and if the 2-row tastes sort of "biscuit-y" and your amber tastes sweet and slightly roasty w/o anything else in it's flavor you should be fine. I have used grain much older than 1 month, although I am quite anal about grain storage, and still made top shelf beer using it. Go for it, there is no time like the present.