Restore a 10.8.2 sparsebundle from a 10.7.5 boot drive?
 

I have an external firewire 800 drive partitioned into two volumes - a boot drive volume with 10.7.5, and a larger, non-bootable volume for holding images. If I boot from the 10.7.5 volume, can I safely restore a computer's internal hard drive with a 10.8.2 sparsebundle that's stored on the larger (external) volume? Or should I upgrade the external 10.7.5 boot drive to a 10.8.2 boot drive to restore a 10.8.2 sparse bundle from the images volume?

You shouldn't back up or restore a system from an earlier OS version. Use that version or later.