If the old image has been overwritten with a new image then someone must have forgot to associate the computer with a new image file / definition. Some of our engineers make this mistake too.
You have only 3 options:
Try a Linux file recovery tool on the FOG server. Upload again from any of the 200+ workstations that has the image. If you can find one that’s not been used great. Recreate the image from scratch.Start backing up your storage node at least 1 a month.