I can recall sending a Rolleiflex 3,5f to Rollei UK in London some 20 years ago for a service. When the camera came back it had also received a 'touch up' of any of the areas where the enamelling was worn.
I spoke to the service department and asked what method they used to touch up cameras and they said they use black car aerosol paints. They simply sprayed a little black paint into a pot and brushed it on. They chose car paints because they dried quickly.
Has anyone ever touched up a camera, what paint did they use and would they recommend it. I personally don't think touching up is a good idea unless there are very minor blemises.
No doubt, I'll get some 'expected' responses.