I've worked on a good deal of camera articles - mostly older film
cameras, though - and have had fairly good luck finding images on
online photo sites like Flickr. A lot of people post pictures of
their own cameras, and I have a pretty good hit rate at persuading
them to allow Creative Commons CC-BY-SA licensing of them.
Another possibility is ebay auction listings - find someone selling
such a camera and ask permission to use their pics.
-Matt