Charles, I like doing gear up as well as it's a little different and allows the model to be displayed in interesting ways depending on the stand. Only downside is sometimes the gear doors don't fit very well into the well if the kit wasn't designed to have them closed.
Cory: Balsa/tissue models are usually not designed for gear up modes. With the balsa models there never is a wheel bay. It's assumed the gear is down and the doors are closed. I suppose you could draw an outline of the wheel bay and paint it black, but some aircraft, like your Spit, show the wheel even when the gear is up. The P-40 comes to mind also. All my balsa/tissue models are hung from the ceiling with thread.