Given how easy the front loader NES is to take apart and the simplicity of its shape, rather than Retrobrite it I would probably be more inclined to just separate the yellowed parts from the remainder and paint them.
But then, you’re also talking to somebody whose OG NES has an emerald green power light and you don’t need to press cartridges down in it to play them anymore. So, preserving that coveted originality is not exactly in my wheelhouse anyway.