My settings: raft, support, 0.2mm, infill 20%. You have to print it in polycarbonate. It's the only plastic both rigid and strong enough to withstand the mechanical needs of that part. PLA is rigid but is not strong. Nylon is strong but it is not rigid. And you have to print in high temperatures (at least 290°C) so the layers get good adherence (essencial to such a tiny part with holes). In my printer I also use horizontal size expansion of -0.08mm to adjust for spread of molten filament. Post-printing: After printing it up and carefully removing the supports (polycarbonate is a tough material, so you have to be careful to not break the part when removing the supports), sand its surface a little then proceed to enlarge/melt the two little 'flap' holes. The original part has one metal rod connecting the holes between these flaps and a spring that connects to the round hole in the middle of the part. In both cases, I suggest that you get a heat gun, heat these metal parts and use them on the print - the rod to adjust the holes, the spring to make it stick in a diagonal angle to the flat face. Why don't I design these holes in the right size? I did, actually. But FDM 3d printing has a know problem with small holes. And in this case the hole is very close to a thin vertical column of plastic, where the FDM anisotropy gets its worst. So if you melt around the hole, its strength gets a lot better. Don't forget to check if the metal rod can slide between the two holes but also has some friction - you'll need it to assemble and disassemble this part.