This only really works if you don't mind losing any other keys (than your own).
gpg -a --export [email protected] > chrisroos-public-gpg.key
gpg -a --export-secret-keys [email protected] > chrisroos-secret-gpg.key
gpg --export-ownertrust > chrisroos-ownertrust-gpg.txt
gpg --import chrisroos-secret-gpg.key
gpg --import-ownertrust chrisroos-ownertrust-gpg.txt