Only the "maps" are missing? what about the other files?
It appears that an "image" from an old (smaller) media, is of course copied block by block into a bigger media: note down that when it reaches into the second (bigger space) media it remained an "image" of a block device. So, I suggest, create a mount point; locate the image where and what name it is; then mount the copied image to a mount point. Clear the issues of permission, making sure you can execute the mounted folders. Thereafter you can browse into it.
Hope this helps.