Yeah, the Anniversary has a different style drop pockets/castings. Are they leather drop pockets or rubber/plastic? Either type will be attached by tacks or nails near the facing. Ideally, the pockets will tuck back right behind the facing. You only want a small nail. A bigger screw would be more that a ball could hit and get chipped on.
If they are leather bucket pockets, check under the rails. There should be a couple of small leather tabs riveted to the front of the pocket. You can screw those to the underside of the frame to hold the pockets in place a little bit better.