Headphone Rest for old Mac pro

I have moved some stuff around in my office and now the thing that I used to hang my headphones on, is gone. I spent the day attempting to hang them up where they used to go and now I'm fed up. I have an old Mac pro, not one of the newfangled cylinders, the large aluminium box, this 'thing' hooks over the front top bar and allows me to hang my headphones where they should be :) I don't know if there is anyone else in a similar predicament, but if so, print yourself a headphone rest and rest easy.