The stock MS25 firmware in the pack is universal stock firmware for all MS25 drives, but you still need to insert your unique KEY. Part of the update process is to reflash your drive from a MS25 to an MS28 (enable firmguard). That is normal. This is why it is important to flashback to stock before updating from pre-13141 dash to post-13141 dash. Because the update can get confused when it sees non-stock firmware on the drive while it is trying to re-flash it.
The big question now is, do you have your key? If not, you may have to fight with the drive in order to get it. It may be badflashed, or corrupted. In both cases, there is still hope that your key is still on there, although it may take a skilled/experienced eye to find it with a hex editor.
Go with simple, first. Set up JF, your PC, and the drive, and see if it just works. Try to read the drive. If it works straight away, cool! If not, read the JF tut for instructions on Badflash. If it reads it, but then says parse failed, then you'll need to either use a hex editor to see if your key is there, or send it to someone who can look at it for you. If that proves impossible, then you might need to send the console to someone who can RGH it and get the key off the motherboard.
Also, check this: http://karma.xzibition.com/~CarpeDiem/update_loop.htm
Hope something here helps! Good luck!