I went ahead and replaced the shell on my most discoloured Dreamcast.

The underside of the original case had become extremely yellowed.

The solution?

Not Retrobright.

I simply moved the Dreamcast into a replacement translucent grey shell.

Problem hidden!

The original case can stay preserved rather than becoming another chemical experiment, and the translucent grey replacement looks pretty good anyway.

The video above shows the swap, and there are more photos in the photo gallery.