On the side of the box there should be a new sticker, white in color, with a upc bar code. It will state "A-Grade" if that's what it is. At least that's what mine said and what all the one's I've seen say. Try a search on
www.gunbroker.com under "hk p7" and look at some of the pictures. There should be one that shows the sticker label. But no guarantees, the dealer might take off the B-Grade sticker and tell you it's an A-Grade. You just have to inspect the gun well.
Like this one: