I did two very different materials, one where I tried adding some rust
(didn’t take a printscreen of the composition before I changed) It’s basically a glossy BSDF which is the metal with the roughness turned up a bit. Then I have a mix shader where the rust comes from a mix of two colors (brownish and some orange color) mixed with some randomness into a and a Diffuse BSDF
The other I did take a printscreen of my material setup and there is probably shorter ways to come to this but anyway it is a voronoi that is turned black and white to get the mixing of a mix shader, and then two different types of glass color.
The lamp
The setup
