I should note....using a morph for a rotating movement like your chest opening is non-optimal. May be hard to understand without diagrams, but here goes why; if you rotate the top, all parts of the top describe a circular arc around the pivot. If you MORPH from closed to open, all parts of the top take a straight-line route from one position to the other. Simply put, the lid will deform. It will look fine closed, and open, but in between will not look right, not at all. In these cases the dead-on simplest solution is to create a figure instead of a prop. The only thing you can not do with a figure is smart-parent it (and I'm not so sure about that, either!) As a figure, you can now apply MAT poses to it, you can apply regular poses (and save them), etc. Of course, you can also chose to simple make two props; a chest, with a lid prop smart-parented to it.