I have the directory and subdirectory formats of the EHD's if you'd like. The problem is that instead of names, Dish assigns a random UUID to each show with other files and a thumbnail. If you can decode where the name is that would be good. At minimum, each show is in it's own sub-directory and after about 2017 has a jpeg thumbnail. Anything recorded has a .thm file which I suspect is also just a jpeg and if you renamed it, it would display.
Worse case you can product a contact sheet of at least the thumbnails on each EHD. But without the name there would to no way to sort.
Also each EHD is broken up into 512MB partitions, and as many partitions as can fit. They seem to write to the disk from the inside out. I.E. If you have 8 partitions, they will try to fill ext8 before they go to ext7, etc. If you delete something, they check if the new recording you are transferring will fit in the free space in the highest partition, if not they go down the chain to find one that will contain the recording.
So if you copy 5 recordings at once to an EHD, they may not, and probably won't be on the same partition but spread out. So you would have to read the entire drive (the reason why my 6TB takes so long to come online, it takes so long that it doesn't finish before the Hopper gets a satellite lock and starts playing a program. So I get a 'You have attached an external drive" message later one. And it persists on any Joey that isn't powered on. So at night, when I go to sleep, my upstairs Joey will always have the frozen 'You have....' screen until you hit enter and then it starts playing. Small annoyance but livable.
I'd be interested to see how you do with your project. The recordings themselves are encrypted so my guess is that the program name might also be. But the thumbnail is not.