[Gogar]

You should be okay if you do that.

YOU MIGHT CONSIDER:

start up your macbook in TARGET DISK MODE; hook it you to your desktop computer with a firewire cable.

Open up the iPhoto on your desktop mac, and select "import" and point it to the iPhoto library on your macbook.

It will prompt you whether or not you want to import "duplicate" photos, and select no, and click the checkbox to "apply to all duplicates". Then, it will import that 5% of photos from your macbook into your desktop mac, and you don't have to sort through them.

Then you'll have ALL the photos on the desktop computer iPhoto . . . . . . .

But your way is fine, too, for sure.