When you saved the project not only was a .duf file written most likely one or more 'assets' where written to the "data" folder.  The easiest way to get just the files you need for a project is to use a specific project library folder.  In your case make a "My Book Project" folder in c:/Users/[user's name]/My Documents/ and map the folder in Content Directory Manager as both Studio and Poser.  Now the important bit, move that library to the top of both Studio and Poser listing.  Copy the Runtime/Texture/... folders/files to the project library and add "Props" folder the project folder.  Under the Props folder you should add a [vendors name] folder and under that a [name of product] folder  Load your object(s) in to Studio and set up the surfaces.  Once everything is ready to save go to File Save as Support Asset Figure/Prop Assets and navigate to the [product name] folder and save.  In the pop-up make sure the Asset Directory is correct (in this example "My Book Project") fill in Vendor Name, Product Name, and Item Name.  For a simple prop you can ignore the metadata stuff.  Hit Accept and everything you need to zip up is all in this one folder with nothing you don't need.  Before closing Studio open Content Directory Manager and move the project library to the bottom of both Studio and Poser lists.