Correct my 3D object

Please create a STL and a STEP file from the attached drawing and rendering of a (half-frozen) meat chopper/separator. Notice there are 4 long blades and 4 short blades in the original unit. The new unit should have the 4 long blades joined to for a cross cutting pattern and the short blades are made longer to have a cutting length of 50% of that of the long blades. It is important that 1) the outline profile of the new unit is exactly the same as the original unit. 2) The joining points have proper radius to avoid accumulation of debris that are hard to wash off. Once the project has started, I expect to receive daily communication including an updated STL file until the final unit is done correctly. The final files will be these following STL, STEP, 2D drawing in PDF, a rendering similar to the one shown. (The STL file I have provided has many mistakes especially the profile of the top 1/2 of the unit. If you use it, make sure you check things carefully.)