after the update my header and background are gone. no telling what else is missing

On any updates up to 3.7.12 you will lose any custom images that are in the atahualpa/images folder as they are overwritten. In 3.7.12 you can now set the default location of images so that you will not lose those images in future updates.

thanks Larry, I'll give it a go. Hope it hasn't messed up anything else.