Hello Astronomicat, and welcome to Seven Forums.
Could you post a screenshot
of your Disk Management (diskmgmt.msc) screen show the full layout of all HDDs? This may be able to help determine why it is including more than your 64GB Windows 7 SSD in the system image.
Backup Complete Computer - Create an Image Backup
Did you move your page file, user profile folder, or user folders to another HDD/partition location other than the default C: ? If so, then those locations would be included in a system image as well, and cannot be unselected until they are moved back to the default location.