How to recover a .txt file from an image of a damaged external hard drive?

I have an old external hard drive that is recognized by Ubuntu but doesn't show the files (just one empty folder and I can't create anything on it)

I went through this, and was able to create an image of the drive with ddrescue.Then using formost on the image file I was able to recover most of my files. https://help.ubuntu.com/community/DataRecovery

However formost doesn't recover .txt files. I also tried Magic Rescue and ntfsundelete which didn't work. Any idea how I can recover txt files from this image or damaged external hard drive?

$ mmls image 
Cannot determine partition type