...Don't Ever Forget to Have Fun!
Robert Grossman is the major manufacturer of parts to restore and repair Marx trains. Should you require Marx parts, best advice is to order a copy of Robert's catalog first, to see a full listing of parts and countless useful illustrations. An extract is illustrated below, to give an idea of what to expect. Should the part you require not be listed, ask anyway, as Robert may have an original used part in stock.
Robert Grossman catalog extract (reduced in size)