Hello,
yes that is correct file.You can use any combinations of FS and customization but must be same(same name).
If your phone was unlocked by patch then it will be locked again after flashing so you will need original sim card to unlock it again.
If it is locked to specific network in your country then it will work after flashing with same sim card.
You can use search button and find topics with "w880 flashing" or "w880 unlock" etc.Don't forget to recharge battery to 100% before flashing.

Regards