The Psion 5MX is pretty old and has issues with the housing - the plastic typically will become brittle over time and certain notches holding the spring hinge are prone to breaking.
Hopefully when tuned/tweaked it will be possible to print it (maybe with MJF?) and be a drop in replacement to give life to broken on units.
Please keep in mind I have not printed this yet, and it would likely require many iterations to get it into a usable state.
Also - It's missing one of the spring holders on the side. It's a mirror of the existing one on the opposite site, so nothing complex, but will be required. It's something I will solve in later versions.
The author marked this model as their own original creation.