Use hot glue or heat mold plastic to attach to the pegs on a 3M mask once you have popped the cover off. Fits small medium and large masks.When applied correctly, the beak does not obstruct vision much more than your nose does already. Print in PETG or PLA with supports as shown in the AMF file.Optionally, you may forgo attaching the beak to the mask, and just let the filters hold it in place. I tried this and it feels pretty sturdy.
Use a hot knife to melt through the linear divots at the corners of the mask, this is where the straps from the original cover/harness will pass through. Use a dot of superglue or hot glue to fix them to themselves in a loop