Well you can right-click the page and select "view source". From there you can click the "commonstyles.css" on line 26, and go through the file to find the background images you need. For example the #header div has a "background:url(/sites/all/files/en/coruscant/main/headerTab_bg.png)".
That means the URL to the header image would be:
Hope I'm not breaking any copyright rules by posting this. If so, I'm sorry, and please delete my post.