That is very cool - I likie!!
A couple of things that caught my attention that could improve the overall effect:
The wood texture on the axle supports are repeating. I'd also vary the color of the different wood pieces to give it some more realism.
The gloss on the wood portion of the wheels throws off the scale in my brain cells. It sorta gives it a laquered toy look. Same goes with the high gloss on the metal part of the wheel (where the 'rubber' meets the road). Too shiny for something carrying a heavy weight on any standard surface.
To give an idea of the scale, if a person was standing in the shot, they would be as tall as the nose needle.
If that's the case, then that must be one skinny dude that can get into that side hatch!

My initial impression (based on the ships window and hatch) that a person would be half or less than that height - halfway up to the middle of the front nose support..... Though if that were the case, then the hatch wheel would be too thick for a human hand...
Anyway, really great model, and it's on its way to being a fantabulous piece. Keep at it!
"Skill without imagination is craftsmanship and gives us many useful objects such as wickerwork picnic baskets. Imagination without skill gives us modern art." - Tom Stoppard
My modern art gallery at:
http://nws.carbonmade.com/