Hi Marc,
As a workaround for your situation, you can download the same assets and sheet info (link to Dropbox below) and basically use them to set a custom theme, similar to how you’d do a custom theme with your own assets, except that these are the “official” iOS7 assets.
If you do this, make sure to use a unique theme name like “widget_theme_ios7_newsuffix”, so it doesn’t attempt to load the default from the core.
https://www.dropbox.com/sh/l4ea2qt0f73x1p3/ctcrLxI8bw
Hope this helps somewhat,
Brent