I'm sure it was Greg who first mentioned this, but we really should have an IRC client or similar real time chatty thing built into the upload page then people can contact an experienced user and ask "what tag do I need ?", or "I've just uploaded image xyz.jpg, can you help me please." and we can deal with everything whilst we've still got access to the uploader, we can get source information, we can ask discreet questions if we think something is wrong.
Also, in response to someone above, PD work is likely being deleted as unused non free stuff because we don't know all the details and can't easily confirm dates and such. You could spend an hour trying to track down one image and it might be a wild goose chase, it might be a waste of time as it still needs deleted, or it might occasionally pay off, but there's simply not enough volunteer time available to try and find the source of a B&W image, find all the creator information and determine whether it's PD or not. There are more important things to do, like reference stuff, or categorise stuff or such. Images are important, but they're not the be all and end all people are making out here.