Showing the facets and angles of the form (Truncated Octagonal Pyramid). The recessions could have to do with propulsion? Wave guides or navigation? (Ref. “Go-Fast” video)
Edges will have to be blended and smoothed over, most joined cleanly, others have a v-groove to solve. Maybe this would be a real-world problem joining plates by weld, if this was not an extrusion method of construction?