How we model and the standards we apply are a choice each of us makes. These are part of mine.
This is an exercise piece to develop my skills in making multiple parts to a specific dimension, soldering and learning to work with more precision. The material is 0.032″ brass sheet. Each hopper was treated as a subassembly, that was soldered with the aid of a jig and a mini-torch. The subassemblies were then joined and soldered.
Where the side panels connect is an important joint. Here you can see that the rear slope sheet is grossly off spec and would leave an unsightly gap if not corrected. The true value of practice pieces like this is training my eye to spot such mistakes as well as developing more deliberate working habits.
My view is that you can work haphazardly or with intention. The choice is yours to make.