stephanP,
Perhaps it would be better if Duane commented here, but apparently at least one of the proto types had a different finishing scheme. I personally chose to follow the original scheme in the spirit of trying to recreate a Simla similar to Ed's. My second Simla will have a paint scheme considerably different from the original.
As far as chosing paint over one of the popular plastic coverings, I just prefer the results I get from painting. It is a lot more work and I have alot more time invested, but it just produces a smoother, sleeker appearance on the finished product. Painted surfaces also do not wringle when exposed to the sun. But of course at altitude and speed no one can see the difference between a painted plane and one that has been covered with plastic

. The down side of painting an airframe is of course the added weight; but with a little effort and practice the weight difference can be overcome to some extent.
Bill