I'm to the point that I'm supposed to rivet the turtle deck to the hull, but I want to make sure I don't run across something later that makes me wish I hadn't done that yet. I reviewed the entire manual looking for tasks that would be easier before that gets on, and going ahead creating the baggage deck was primarily what I found. I created a support structure underneath it, so it will hold whatever you throw at it. Also, at the very back, if you don't place a block underneath to give it some elevation so it meets up with the back of the turtle deck, you'll have an unsightly hole to the back of the hull, that things could fall into and potentially be lost forever.
Fitting the baggage compartment under the turtle deck.
Easier to do now, before I rivet down that deck.
Wood support structure screwed and glued underneath.