Too much labor!
Have you given a thought of moving the whole library instead?
Can you have it on a fast USB stick and move the whole thing? Or on an external HDD?
All you have to do is to press and hold OPTION while launching Aperture on any of your Macs and pick the library when prompted. That way, you'd never have to move anything between libraries.
Or have the MBP running and connect to it remotely via WIFI, then you could see its HDD on the iMac and work the files via file sharing?
This is actually quite easy with Aperture 3. On the laptop, you can export specific projects. Just select it on the laptop and select "Export->Project as new Library." Then copy that exported file to the desktop, and use File->Import Project/Library.
The project will be imported, with all photos, keywords, and adjustments intact.
Note with Aperture 3 this can also be done "round trip" if you want. i.e. you can export a project as a library from your desktop, copy it to the laptop, import it there, work on stuff while you're away, and then do the reverse. When you import it back into the desktop, it will actually update all the photos in the desktop with the new adjustments! It's quite slick. There's a bit of copying and work required so I wouldn't do it constantly, but I've found it very helpful on occasion.