[Galaxy Note II Android Development] oalex:
I am in similar shoes. So hopping for a solution.

Edit: I got it sorted out with KIES. Who would have thought.

It might be the way to go for you too.

So here goes for people that need to go back to old firmware (Stock, Kies and Warranty ready), but only have backup of new EFS. Also their region doenst have official DMG1 modem.

If all that sounded familiar, then this guide is for you

1. I was like you on latest Custom, rooted rom.

2. I decided to go back to stock (region Hungary): : PDA:ME6 / PHONE:MF1 / CSC:MF1

3. I followed Dr.Ketans guide to downgrade/remove root, counter reset, etc.

4. Everything when't fine till I finished and tried to use phone. There was not network, due to EFS getting messed up by downgrade (I had backup, but just like you and others, it did not work with older modem MF1 vs. DMG1).

5. Tried everything you did all day. Nothing worked to repair EFS.

6. Only way phone was ok (that is IMEI was fine) was if I flashed/upgraded only modem (DMG1) with Odin. But this was not available for my region.

7. However (and I guess this is your problem too) with step 6. I get version mismatch for CSC. Not something you would notice ordinarily, only that Kies wouldn't recognize my phone.So same "no warranty BS".

8. Other option was to use another regions firmware, but then I still was worried about warranty being offset if I ever had to take it to SS.

9. I tried everything I could find on the net (especially XDA) with no avail.

10. Then while I was waiting for another stock rom to download (you know how slow SAMmobile is). I started playing around with KIES again in the background.

11. You know the problem was it never recognized the phone if I connected it, because of the csc as mentioned before.

12. I now looked at the option under Tools => Firmware Upgrade and Initialization. I thought what the hell, I would probably not get fas as the version mismatch would not let is connect.

13. However to my surprise, that menu item started asking for things like: Phone model, then: Serial number (see on the back of the phone, under the battery). I tough to my self, this seems interesting.

14. When I entered the information it displayed the correct version stuff for my region. : PDA:ME6 / PHONE:MF1 / CSC:MF1 and asked "if I wanted to continue?" and to save my stuff, blablabla.

15. Again I was not giving it any particular hope as I already downloaded (And flashed) the stock official firmware from SAMmobile, but said to myself what the hell.

16. Kies asked me to enter DownloadMode. I did, connected the device and started the firmware up(down)grade.

17. For one it was obviously much faster than SAMMobile to download.

18. At this stage I was sure this would wok fine, but I will be faced the same problem as with the ODIN flash. EFS will be messed up due to downgrade. MY EFS backup did not work with MF1. I tried that before as mentioned.

19.....flashing finished.....phone rebooted......I prayed.

.

.

20. BOOM network connected. OMG. Everything is fine, IMEI (even after downgrade from G1 to F1), CSC (no more version mismatch), Kies recognizes my phone.

All is well. Now to patiently wait for Samsung to release the 4.3 this month.

I hope this help you too. Its funny how we have all the guides and apps. Meanwhile the software considered the antichrist (slow, buggy, inflexible, useless, not mentioned in any guide) is the one that fixed the efs stuff up the best.