Design a Moleskine GTD System?

I was really fascinated by the Moleskine City notebook and everything they were able to pack into something that is just a bit bigger than a normal Moleskine.

It got me thinking....

How would you design a single Moleskine that let one implement the entire GTD system?

In order to do this it would need the following:

1. A set of plain pages for an "inbox".

2. A full year weekly calendar big enough for appointments and date reminders.

3. A contacts list for phone numbers and contact information.

4. A place for project lists, waiting for lists, and someday maybes.

5. A place for next action lists and Agendas.

Some of these are really best as loose leaf items, like the next action lists and agendas. Currently I use notecards for this. How could loose leaf material best work in a Moleskine? I have this vision of tiny little rings but thats probably impractical.

How can a single notebook have multiple pullout parts? I have another vision of three or four Cahier style notebooks all bound together in a normal Moleskine cover.

So what thoughts do you folks have for a single GTD Moleskine device similar to the city notebook that would remain practical?