Several years ago I attempted to fix a broken power switch on my Zaurus SL-C750. After reassembly, there was a loud clicking sound every time I closed it. Recently, I noticed the case was cracked in several places.
My plan was to open the Zaurus, skim the case with epoxy glue in the cracked places and use a craft knife to trim back any excess.
To open the Zaurus:
Underneath the display hinge I discovered the screw post had sheared off. This probably occured the first time I opened the case. The stress of closing the display had caused the case to crack.
I glued the display hinge in place and tried to build up a layer of glue on both the inside and outside of the case where it had cracked. I also tried to build up glue around the damaged screw hole in the case.
Epoxy glue is too hard to trim with a craft knife. Trimming was a complete failure. It's also very hard to apply epoxy in thin layers. During reassembly, almost all the glue on the outside cracked and fell off. Although I didn't use a lot of glue on the hinge, the case didn't fit together well.
The case is too thin to do this kind of repair. One of the clip points is in the middle of the serial connector hole and it is very difficult to reassemble the case to fit around the headphone socket. If you have similar damage it would be better to replace the case, however, you may crack the new case during reassembly anyway.
Looking to the future, making a new 3D printed case would probably be the best solution, if you could measure and manufacture it with enough accuracy.