With respect to mechanical bodies, it is a good idea to exercise the shutters monthly, going from B to the top shutter speed. Otherwise, they may wind up being inaccurate. Definitely leave the shutter uncocked. At least, with a couple AF SLR's, it is possible to store them uncocked. One is the Maxxum 9000, since it's the only true AF camera body that still has manual wind, the other being the F4. On the F4, fire the shutter on "T", then turn off the camera. Move the shutter speed dial to any position other than "T", and the shutter closes. Only problem is that the mirror remains up. Guess you could then turn the mirror lockup lever to the locked position, which might relieve some of the stress on the mechanism.