When I need "more" pictures of something, I rely on the trusty internet to help me out. Just do a search using the right 'key words' and I bet you'll find all sorts of pictures. Save them to your computer and print them just like the photos you took with your digi camera. Some will be sharper than others, depending upon how they were saved (saved for internet, versus saved in full resolution), but usually good enough to scrapbook with, in either case.
I am currently working on a 9/11 Tribute scrapbook. I was not there in person so, of course, did not have any of my own photos of the "attacks" or the "results", but found hundreds of high quality photos online to download, print and use in my book.
After seeing some of my pages, the ladies I scrapbook with have all started using the internet to add to their collection of photos when the ones they have either didn't come out as well as they'd hoped, or they just need more of them! My friend, Shirley, needed some pictures of the Osbourne Light Show (not sure of the official name), because hers didn't come out...I showed her how to find them online and she went CRAZY! She has a whole bunch of great pictures now, some taken by professional photographers, showing what her pictures would have shown had they come out better.
Just my two cents about how I get around this type of problem. Good luck and happy scrapping!