Help!! What is this box?

We shopped from ads in the back of magazines
I remember being in denial that the car was old enough/rare enough/ etc to have to use the big yellow Hemmings - but eventually I did. Yup. Went to dealers with parts managers that had the parts books and would help me out or even let me use them. Took lots of notes and made made sketches. Then with the part number would go through page after page of small print ads. Got a few things that way that I couldn't find by other means.