Compact blade cover that converts to a handle when opened. Slide the cover off, flip 180° and cap the other end to make the handle.
USE CAUTION when handling blades and assembling this part.
EDIT with Onshape (must have a free or paid account)
First insert the blade in to the 'handle' part. Then slide on the 'lock'. If it is too loose, you can shim it with a small piece of paper, or add a small dot of glue for a more permanent fit. The 'cover' fits over the blade, and also on the butt end of the blade. Since the design is symmetrical, the cover can fit onto the butt end in two different orientations.