My old Olfa cutter's slider broke its pin off (the little nubben that attaches to the blade), so I had to try to make a replacement part. 

Because of the shape, and to improve the strength, I split the model down the middle in Prusa Slicer and printed it in 2 halves, then glued them together. 

Because the part is quite small, it may not adhere properly to the print bed, so a skirt may help. I managed to print it with a 0.6 nozzle at 0.2mm layer height. Set it to 6 vertical shell perimeters so the part is solid. A little sanding and filing will make sure the part slides properly and the nubben fits the hole in the blade.

Needs an M3 insert for the tightening screw.