CMP Garands are anything but a "pig in a poke."
CMP armorers thoroughly go through all the rifles they sell, check function and barrel muzzle/throat wear, and grade the condition. In general, the actual rifles tend to be a much better than their grade definitions.
On the very rare circumstance you encounter a problem, CMP customer service is second to none. Once, I noticed one a small blemish on one of my gas plugs (that had probably been there since it was manufactured in the '40s). I sent a email to the CMP, they mailed a new plug out, and I had it in my hand less than 2 days later.