To remedy a case of corrupted gpg keys on Linux (if you have the GPGKeys elsewhere):
First create a ‘Backup’ [on Windows, via the GPG4Win > GNU Privacy Assistant (GPA)].
Next, copy the backup file to Linux & on Linux, run:
gpg –import /path/to/backup/file
.Lastly, set the necessary level of trust:
$ gpg --edit-key <uid>; gpg> trust ... 1 = I don't know or won't say 2 = I do NOT trust 3 = I trust marginally 4 = I trust fully 5 = I trust ultimately m = back to the main menu ... Your decision? 1 gpg> quit
Thankfully, a trusted Windows machine had GPG4Win which allowed me to export the key and saving my day!