Is there a way to make a round to a rectangle

[AnnoNiem]

I don’t have any practical experience with 3d printing (yet), but it has my attention
So i’ve made an attempt to re-draw your model, as follows:

1. your model as reference
   
   
2. first face
   
   
3. pushpulled bucket
   
   
4. determined parts
   
   
5. pushpulled parts
   
   
6. moved connecting funnel edges to depth
   
   
7. added wholes
   
   
8. xray finished part
   
   

What was the result of the last attempt, did you manage to print the model?