A CR2032 battery near the audio heat sinks stores settings, etc. If this part leaks, it can corrode the rest of the PCB, so keep an eye on the battery from time to time, and consider removing it before placing it in long-term storage.

The Region is encoded in the BIOS, which is contained on a 27C040 EPROM (or compatible mask / OTP ROM).

If the color balance seems to shift based on the contents of the screen, then it is recommended to replace three capacitors. This is not from age, but rather a matter of incorrectly specced parts.

Capacitors C45, C46, and C47 are in series with the RGB output from the video DAC. They are 10uf 16v caps. In my experience, replacing these with 220uF 16v caps resolved all color issues I had.