The model is functional, but it has two small shortcomings. The design of the small box cover was dictated by the size of the large box that I sized to the maximum limit of the printer bed and the fact that I didn't want to use a stand. The handle and lid open one at a time. Later we added the guide rails that are mandatory. I didn't make the guide directly on the large box so as not to exceed the maximum limit of the print bed. We have attached the file from FreeCAD where you can make changes: for example guide directly on the large box, change the lid hinges, change the handle or the gauge dimensions as you wish. The handle supports a respectable weight, without being abrupt by inertia.
You count the number of parts needed for assembly :). Success!