Fuselage remix - integral frames and stringers

Re-mix of billbo1958 Main Body Front Fuselage, to add inner surface stiffening features, and also integrating a further three parts (Main Body Connecter & Nose Shell x2) into a single component part.

This is intended as a mini-project to:
a) Improve my 3D printing skills, especially for thin-wall parts.
b) Ensure the best use of lightweight Colorfabb LW-PLA filament (this material expands by foaming inside the extruder, reducing filament consumption & therefore final weight)
c) Develop CAD solid modelling methods in Fusion 360 in support of a&b that ensures (i) full definition of all required features, (ii) close representation final printed part and (iii) outputs a fully parametric meshed surface model in STL format for 3D printing.

Fusion 360 part now contains three components:-
CAD Nominal
Manufactured Part
CAD Nominal Print Mesh

The re-mixed 3D printed part now carries both outside and inside features and does not rely on the chosen slicer for any feature or basic