Unfortunately, only one screw diameter

All little screw have the same diameter: 1.2 mm.

Lengths are in mm: 1,6; 2.0; 2.5; 3.0; 3.5; 4.0; 4.5; 5.0; 5.5 and 6.0 mm.

No single cog which I can use. In addition, the screw heads are so small that even my smallest watchmakers screwdriver for or is too large.