Sorry for the delay. The knife is a nisshu brand 'hori hori'. The markings on the left are inches (1-6). The markings on the right are mm (in increments of 5mm: 25mm - 150mm). I took other photos at the time - likely not as in focus - but I'll see if I can find any with a side view. I remember I had issues with a breeze when I tried to photograph it. The seedhead kept moving and the seeds kept blowing off the knife. If I find any suitable I'll upload.
It's great to see one actually reproducing in nature - all of the pods in the area I check out occasionally (connecting area between Mts Ainslie & Majura, mostly NE of Bragg St. park) got eaten, and there weren't very many to begin with.