Well, as I see it, you add the file. That is one version. Then you take the file, change it values and update them. That's the second version. Perhaps it would be a better way, to create the Item and add the file to it, change the properties and the add it to the list. I didn't tried it yet, so it may be wrong, but I think I did it once in that way.
Author of Primary ROleplaying SysTem How do I take my coffee? Black as midnight on a moonless night. War doesn't determine who's right. War determines who's left.