Leonardo Da Vinci to give him his full name, sometime ago I stumbled across this strange looking model, and managed to buy one cheap, this is Academy non-scale (at a guess 1-35) wood finish as seen and fully working, taking about 30 minutes to build, appeal to kids both small and BIG non-glue and non-paint simply snap together.

Da Vinci 013 by warship, on Flickr

Da Vinci 002 by warship, on Flickr

Da Vinci 023 by warship, on Flickr
There are many other Da Vinci models to buy on the market, maybe a good start point for a complete beginner as basically nothing to go wrong. If I were to buy another one, would I paint it ? To be honest, the wood effect looks quite good, and a very light lick of paint could bring out the grain.
Many of his inventions were imagination and never left the drawing-board, he was hundreds of years ahead of his hime, no shadow of doubt about that, and while the Earth occupied the centre of everything, he believed to be different.
I hope you enjoy this model as much I did in building it.

Thanks for posting. I was going to get this for my kids, along with the others in the series.