Based on the answers provided, the model needs to make the following corrections to the 3D object:

1. Include a second sector with a smaller radius, centered at the same point as the original sector. This detail is currently unclear in the object.

2. The second sector should be negatively extruded to create a cutout in the original object. This feature is currently not evident in the object. 

By implementing these changes, the object will maintain its resemblance to a sector of a circle and a small sector from a hollow-cylinder, while also clearly showing a second, smaller sector and a cutout.