My friend broke the original paper taper that came with the paper guillotine machine.
I took a photo of the original design and modeled something very similar, since this form factor worked perfectly for the application.

I looked for this tool everywhere and could not find it anywhere.
Google Lens did return a result from a Polish website, but it did not provide any useful information, just a photo and some measurements. Because of that, I honestly do not even know what this tool is actually called. On the site (the screenshot is included among the pictures), it was described as a paper tapping tool that allows you to precisely align and tap a stack of sheets onto the table.

I printed it in PETG (Azure Film) with 3 walls and 20% infill.
It is strong enough and survives a drop test.