I watch all the videos from this fellow but I don't know his name. He has some great box & bag openings with used trains that he either gets from Ebay or the many resale shops he visits. In a lot of his videos I see him using this white pen to remove marks on these trains. It must be some kind of eraser with a solution in it. Does anyone know what it is, what it is called or where we could get one?
https://www.youtube.com/watch?v=LKFfMaDnuFs
https://www.youtube.com/watch?v=LKFfMaDnuFs