Where can I go to have my Frederick Cooper lamps repaired?

I have two Frederick Cooper lamps that were given to me about 10 years ago. They are candlestick style. One needs a harp so the shade can be attached, the other one also needs a harp but also needs some work done to the silk beaded shade. Since Cooper lamps tend to not have universal parts, where can I get these harps and also have the work done on the shade? I am in Chicago but I would be willing to work with any shop, even if it wasnt local.