Vintage "Corda" wall light by Jo Hammerborg for Fog & Mørup, Denmark, 1960s

The "Corda" wall lamp was created in 1967 as a slightly more luxurious version of the "Alfa". It was made in 3 colors and this is the copper version. The light has a matte black square base and brushed copper arm and shade. Unfortunatley this lamp has a stain on one side. I am not sure if this can be removed with the right product. I have set the light to almost half price due to this.