Media Library Not Showing Uploads

Hello Folks, Hope someone can assist.

I recently created a mirror site and imported all existing content over. Now I’m having a problem with the Media Library. I have about 300 media objects (images and documents), but only about 60 are showing up in the Media Library display. I’ve confirmed all objects are in the correct directories, and these directories mirror the original site. They’re just not sowing up in the Media Library display.

Is there a way I can manually pull these in?

Thanks,
Ron