First off, I'd like to congratulate you on a job well done. It seems as though you've spent a lot of time on this piece.
I love the steampunk attribute combined with the rain-- it adds a wonderful feel to the piece, something that can't be replicated.
The story behind this piece is incredible. Entire fanfictions could be written and none of them would do it any justice.
Now to the points of improvement, why I really wanted to write this critique.
For my easily-satisfied taste, the piece is perfect, but from a critical point of view, there is too much going on in it. Perhaps it is the neck that sets it off, or else the zeppelins in the background. Any way it is, the work should, perhaps, have been constructed with a more discerning hand.
Other than that, it is an excellent work.