I'm trying to clean up some old iron lamps a railroad lantern.Does anyone know what I might use on them?

A mix of light oil (3 in 1) and paraffin (kerosene) 1:2, applied with varying grades of wire wool and lots of elbow grease. If you protect yourself (goggles glove etc) you can use a powertool with wire brush or flapwheel. Just use soap and water on the glq or a non scratch cream cleaner like Cif.