Based on your revisions, I definitely agree that the concept has clicked quite nicely - you're showing a lot more patience and care in how you lay out those subdivided grids and gradually build each construction out. I can see where you're talking about being somewhat uncertain of how to translate curving surfaces based on their various orthographic plans. While this is something that will improve with practice, I think the main issue I'm seeing is that on that bottom right corner drawing, you appear to have placed all of your points right on the side plane of the bounding box, when in fact many of them were further back.

In order to place them in 3D space, you need to first find to points on the side and front planes, then use them to determine the actual position in 3D space, as shown here. It's worth mentioning that I picked totally random positions, and didn't reference the actual ones in your orthographic plans - it's just an example of how to combine the side view and front view.

Anyway, I'm quite pleased with your progress, and will happily mark this lesson as complete.