I am about to lose you all here because of snow on my satellite so I will make this quick.
If you need my Photoshop resizer action to make it smaller you can get that HERE.
To download the Backgrounds....
Preview opens at 1680x1050
Make sure you change the following line in your Tumblr Custom HTML
top left fixed repeat to this top left fixed no-repeat
If you need help with adding a background FOLLOW THIS LINK.