This is my second attempt, and a rather difficult one. Detailed information was very hard to obtain, but I managed to piece something together. Tear it apart please, this is my second attempt at an accurate metal finish (for me at least).
Add some shading up to mid fuselage level. This makes it look rounder and also more metallic.
Added a sharper highlight about 3/4 ways up the fuselage.
Added some reflected light on the bottom of the fuselage. This is more realistic. (It will also make Blowhard happy. Now he's your friend and you can ask him to finish the drawing for you. That's a very easy and effective way to draw profiles. )
I think you also want to correct your rudder, which looks concave. Also, the wing fences need reworking. I modified the outer one by making it darker and reducing the black gradient. This way it still is apparent but doesn't seem as "bent".
You've already understood the basics. I think these few simple additions should enhance the drawing. Probably other simmers can help improve it too.
the first thing that cathed my eyes is the wing. That shadow running all along the wing is too wrapping: need a thin light to highlight it. I am in a rush so can't make any example right now, wish it's clear enough anyway
Ok. I have yet to rework the wing edge highlighting, but I managed to make the fuselage a bit more rounded looking (Thanks gamary). I toned the wing fences down a bit to make them look less "bent". The plane looks much better with a few simple tricks, thank you!