What is Reddit's opinion of
"Ultra Sharp Diamond Sharpening Stone Set - 8 x 3 Coarse/Medium/Extra Fine"
2 comments of this product found across Reddit:
Diamond Machining Technology (DMT) makes 8" x 3" plates (example). Other companies do also (example). These are just wide enough for a #7 and #8 blade, I believe. But they are not cheap.