Why would you take a NAND off another board before doing a lot more work to try and get it working? You probably messed up the soldering if you don't even know how to flash it properly , no offense im just saying.
I have done all of mine with an LPT cable and only one has ever failed too boot , and i also accidently deleted my original flash , but all you need is the Kv and Config you don't HAVE to have the backup it is just for safety , you do have to have the kv and config however. You are also supposed to dump multiple times to check for bad blocks , if you keep getting the same one or ones just write your Kv and Config too the XBR image and flash it , and it will be fine. In my case the bad block i had that was causing my problems was physically in the chip as i could not read write or erase that block it would get halfway through the boot animation and then give me e79 , I had an xbox 1 with almost the exact same problem and an xecuter modchip fixed it , you could try an older cygnos with the dual NAND instead of trying to swap it off another board.