I bought one of Andy's DIY leather Grado headbands. I have yet to install it (HF-1 out on loan), but it's gorgeous. Quality craftsmanship and it feels like it should be very comfy. If Andy chooses to make more of these he could be a serious asset to the Grado-owning Head-Fi community. Great experience.
Update: I installed the headband using Andy's detailed instructions and the result is awesome. The fit is perfect, and comfort is terrific. Finally the HF-1 looks and feels like a quality pair of headphones.