This is a great idea, I will look at the textures of this plane and ask permission to use them if I like them.
I agree on the maiden flight they will be so clean in real life and I can see the appeal 
however its tough to keep them that way when flying in polluted air, rain, landing on slushy runways have a storm etc. Having said that some airlines do take better care of their planes than others!
The dirtiest planes Ive been on IRL have belonged to Air France. I saw one of their 777s that looked like it had been taken offroading lol.
Thanks for your idea and for the link to the dirty texture! I will just ask permission, no need for me to reinvent the wheel!