Merging a Crypt7 and a Crypt8 whatsapp backup

I have been searching a lot in the past couple of weeks on how to merge two whatsapp backup. Last month I got a new phone, installed whatsapp along with my old backup. During installation, whatsapp said, "backup found" and an option to restore. I clicked on it, it was processing for a very long time and then said backup cannot be restored :(

I started using whatsapp on this new phone and observed that the present database type is Crypt8 and my old database was of Crypt7 type (may be that it why the messages were not restored). I have still kept my old backup. Can anyone please tell me how can I merge these two databases (old Crypt7 and new Crypt8) or is there any other file that I need to consider?

I also rooted my phone to get access to com.whatsapp folder. Found it in the root @ data/data/com.whatsapp

File structure on the root

+ com.whatsapp
  + cache
  + databases
    - axolotl.db
    - axolotl.db-shm
    - axolotl.db-wal
    - msgstore.db
    - msgstore.db-journal
    - wa.db
    - wa.db-shm
    - wa.db-wal
  + files
  + lib
  + shared_pref

File structure on SDCard (old backup )

+ WhatsApp
  + Databases
    - msgstore.db.crypt7
    - msgstore-2014-11-17.1.db.crypt7
    - msgstore-2014-11-18.1.db.crypt7
    - msgstore-2014-11-19.1.db.crypt7
    - msgstore-2014-11-20.1.db.crypt7
    - msgstore-2014-11-21.1.db.crypt7
    - msgstore-2014-11-22.1.db.crypt7
    - msgstore-2014-11-23.1.db.crypt7
    - msgstore-2014-11-24.1.db.crypt7
  + Media
  + Profile Pictures

File structure on SDCard (present backup )

+ WhatsApp
  + .Shared
  + .trash
  + Databases
    - msgstore.db.crypt8
    - msgstore-2014-12-9.1.db.crypt8
    - msgstore-2014-12-10.1.db.crypt8
    - msgstore-2014-12-11.1.db.crypt8
    - msgstore-2014-12-12.1.db.crypt8
    - msgstore-2014-12-13.1.db.crypt8
    - msgstore-2014-12-14.1.db.crypt8
    - msgstore-2014-12-15.1.db.crypt8
    - msgstore-2014-12-16.1.db.crypt8
  + Media
  + Profile Pictures