Does a mfg date really matter? The N's never had any major issues or recall's. If it is a good deal, then buy it. I have two N's, which I bought almost 6 months apart, and coast to coast opposite of each other. They have a 52 digit difference in serial numbers. Both are from the 407xxx batch. Kind of ironic, but otherwise, they are bodies, and I use them to capture images. I don't treat my bodies nor lenses, like they are priceless pieces of art. They are made to get used, so I use them.
Don't sweat the mfg date, if you can even find out when they were made. Plus, don't worry about shutter counts. The lower the shutter count, they more you will pay. Worst case scenario, is you will eventually buy a new shutter for about $300. Then your body will last another few years.
