Second Lamp piece all ready to go and both pieces are coloured in.
Many metal surfaces, particularly brushed metal, tends to stretch the light vertically to the point of making it look like lines across the objects surface. I do not expect we will be covering this in this section (if at all), but what method would one use to reproduce this effect?
My lamp thus far:
Do you mean anisotropic effects? Brushed metal surface? There is a node for that!
Oooo! Do tell! 
Anisotropic BDSF, replace the Principled.
Though you can use the Principled as it has the anisotropic slider too, and rotation for it. Not sure why the separate one exists. I think the anisotropic is stronger in the special node?
First no anisotropic with Principled
Second with anisotropic using the special node. .45:.5;.33
