Amey, which files do you need in this folder for windows to restore the backup on first opening of whatsapp? I have this message.db file from my own phone and placed it on my new phone sd card with the folder structure you describe, and the phone does indeed recognise and attempts to restore. But it says 0 messages were restored! I am wondering if i need any associated files in any specific structure for it to actually recover the messages... please let me know if you can help, i've tried seemingly everything!
Ciao