Duplicity restore with ftplicity fails because of different volume gpg key

Question

I'm trying restore my backup made on remote ftp server but i have problem because backup was made with different gpg key and then incremental backups was made with second gpg key. I get

/usr/local/bin/ftplicity backup restore /home
Start ftplicity v1.4.2.1, time is 05/05/15 10:41:35.
Using profile '/root/.ftplicity/backup'.
Using installed duplicity version 0.6.18, gpg 1.4.12 (Home: ~/.gnupg)
Test - Encryption with key 12345678 (OK)
Test - Decryption with key 12345678 (OK)
Test - Compare Original w/ Decryption (OK)
Cleanup - Delete '/tmp/ftplicity.25274.1430815295_*'(OK)

--- Start running command RESTORE (10:41:35.239) ---
Running duplicity - FAILED (code 22)
Output: NcFTP version is 3.2.5
Local and Remote metadata are synchronized, no sync needed.
Last full backup date: Tue Oct  1 20:42:41 2013
Volume was signed by key 87654321, not 12345678
--- Finished (10:41:52.348) - Runtime 00:00:17.108 ---

I have both gpg keys but using this: 12345678 key but before i was using 87654321 and now i cant restore backups.

Making backup going OK there is problem with restore or simple fetch file from backup because of

Volume was signed by key 87654321, not 12345678

let me know