I also have a LE trade-in P229 DAK. You can use P226 magazines in the P229. In .40/.357, both magazines are the same capacity, 12 rounds, but the P226 magazine extends about 1/4 inch below the frame of the P229. The P226 magazines that I have (SIG and Mec-Gar) all have the flat base plate, while the P229 magazines have an extended plastic plate. I don't have any vertical movement of the P226 magazine in the P229 frame, although there is a slight amount of side-to-side movement at the base.
Mine came with the Hogue wrap-around grips too. I don't know if they were supplied to the user agencies with the grips in place, but on my pistol, it is apparent they were never removed. The anodizing on the front strap is worn away, although the horizontal grooving is relatively undamaged. There aren't many options for DAK grips, so I use standard DA/SA SIG factory grips on mine.
Mine came with the Hogue wrap-around grips too. I don't know if they were supplied to the user agencies with the grips in place, but on my pistol, it is apparent they were never removed. The anodizing on the front strap is worn away, although the horizontal grooving is relatively undamaged. There aren't many options for DAK grips, so I use standard DA/SA SIG factory grips on mine.