I either need the contraption or to get a lot better at math. But I took some more measurements anyway. The is frame hiding 8-9 pixels of paper under the bevel total. Appears to shift 6 pixels on the left edge towards the right. The right edge appears to grow 14 pixels. Now I am lost on where to go to really prove anything but 14+6=20 pixels which is the offset I measured and seems to support the idea that the shredder was angled. Why do I click on conspiracy theories?! I need to go do something productive now XD