Theme page headers and rotator images not assigned after website migration

The XML export/import feature does not transfer the uploads folder inside the wp-content. So you need to transfer those too to your new site from old site. I think following the below steps from ground up will be better-

1. First zip the wp-content folder or directory and download it.
2. Then backup the database.
3. After backing up the database, download the database after cleaning the WordPress serialized data. I use this tool. And it works pretty well. You can also do that after downloading the database with any text editor. But the first way is pretty safe cause WordPress saves many serialized data in database.
4. Then install fresh copy of WordPress in your new server with a fresh database.
5. Then replace the new installation wp-content folder with your previously downloaded one.
6. After that delete all the table from new database and import the downloaded database. May be some time you also will be needed to delete the new database then create another one with the same name and downloaded database SQL file. But it depends how you downloaded the database.
7. Lastly you need login to the wp-admin, then have to go to Settings >> Permalinks and then have to hit Save Changes. It will re-generate your .htaccess file.

Hope that thing helps.