Have you played the game of Chess ??. One can teach you the moves, but making them useful is your own concern. You can't learn from a watching a chess game played b/w two individuals instead of playing yourself; Similarly learning from a single USEFUL project as you said, won't help. You need to delve into your own requirements and make a project out of it.
Every project has his own requirements. Seldom, you will find a project using all the features of the language. Therefore, the books focus on the basic features, rather than taking a project and reading out.
To be honest with you, I too searched for a working sample of WPF application when i had to make one few months ago. Found nothing and then read from the books and internet and got things rolling.
And the last thing is that these already made applications or projects make you more confused than ever, because they are made by professionals who have their own styling and tweaks. To get to that level, you need to forget about everything else and just start coding and later on StackOverflow is always there to help you out.