Here's some context: I recently flashed to CM 11. Everything's running great, it's my daily driver, and I love it. It's easily the best, most smooth ROM I've ever used but I recently discovered a need to flash back to the stock ROM backup I was running pre-CM 11. Before I flashed to CM 11 I was running the standard JB stock and incidentally I was also using a different Kik username. After flashing to CM 11 and installing Kik, I decided to make a new username. Now, given that I never logged out of that old username (the one I was using on JB stock), I know that if I were to flash back to that old ROM, I'd boot into a ROM that's logged into that old account. I need to be able to do this because I need to access that old Kik account's chat logs for personal reasons. My problem now is due to two issues: my amazing stupidity and...well, no that's really it.
At the time I was running stock I was running CWM recovery. I made a backup using Rom Manager but like an idiot I backed up to my internal SD card. In order to flash to CM 11 I had to wipe my internal memory, which eventually lead to me losing that backup. My only silver lining is this: I made one backup to external sd about a week before I flashed to CM 11.
Here's where it gets messy: Not knowing that the backup on the external sd was for my stock pre-CM 11 ROM, I stupidly deleted it to free up space and began saving files onto the external sd card. After I had flashed to CM 11 I made about three CM 11 backups. I deleted my pre-CM 11 backup because I mistook it for one of these three CM 11 backups. Upon realizing the height of my stupidity, I just finished recovering these lost folders and files using a data recovery program, but I have no idea whether or not the files have been irreparably corrupted. Is there any way I can verify that this backup is still good to use? I don't want to risk attempting to flash back to my old ROM only to have it wind up bricking my phone. Does anyone know of a good way I can figure this out? Any help is appreciated.