Blades printed at 0.2mm layer, 4mm nozzle, 2 walls, with 100% infill. Print 42. 

If your prints are accurate they should all fit together without much friction. If you have slight over extrusion, either sand them down or try removing one of the blades.

The case top and bottom are in the same file.

I printed at 0.2mm layer, 4mm nozzle with 3 walls.  2 walls would work. It requires 5 x M3 16mm button heads and 5x M3 nuts. 

I used some painters tape inside the case to add some lateral friction to the blades sliding in and out.

Print Spring and Lever (See Below)

All credit to Tjaf this is a minor change to a great model. Please see Tjaf's model page to get more detailed info. see the original design and to pick up the Spring and lever for completion to this remix. I recommend the 2mm Lever. Print both in petg, to reduce wear and have a little flex without breaking.

https://www.printables.com/model/57209-lockable-contour-gauge