I have a newly installed Ubuntu 17.10 and do want to recover my private pgp keys from an already extracted duplicity backup. How to accomplish this task?
I found my solution here.
Private keys can be recovered by moving .key files from old to new private-keys-v1.d folder and restarting gnupg.
mv ~/backup/home/user123/.gnupg/private-keys-v1.d/*.key ~/.gnupg/private-keys-v1.d/
Public keys can be restored from keyservers using enigmails keymanager.