[Evolution] how to merge messed up backups

[White_R <bruno anche no>]

hi all!
(I'm using debian stable --> evolution 2.22.3.1)

Because of my lack of attention I'm in a strange situation.
I have a full .evolution backup of 2010/05/05 and one of 2010/06/21.

My problem is that on 2010/06/22 I 'restored' from the older backup, and
since then (obviously) I've never been able to access my mail of the
2010/05/06~2010/06/21 period.

Would it work if I extract from  mail/local/Inbox and mail/local/Sent
(from the 2010/06/21 backup) the messages of the 'dark' period and paste
them in my ~/.evolution/mail/local/ files?

Thank you for your attention,
bruno