I'm not a huge fan of Lego system, but there are some projects like yours, that I really admire.
There's used a lot of precision to position the bricks and axes, wheels...etc. combined to a perfect looking picture according to the movie.
I especially like the cabine opening as a "rose". It's not only the outer interior, but also the funcions resemble ti the real thing.
your tumbler is realy awesome ^^! you made it perfectly. Can you please give us intruction to create your Tumbler! As many i'have tried to create my own but not as perfect as yours :/
thank to think about it!