Putting all the files into .gnupg folder didn't work even after a reboot (even though it was a direct backup of this directory).
However, when I then tried to generate a new one in the terminal using the following:
gpg --gen-key
And following the steps there, it created a key successfully AND when opening seahorse again... the old key was discovered too!
I've attached a screenshot of this too - the highlighted one is the new one and I've censored the email address from the new one because I don't want it being public.
Further information...
Putting all the files into .gnupg folder didn't work even after a reboot (even though it was a direct backup of this directory).
However, when I then tried to generate a new one in the terminal using the following:
gpg --gen-key
And following the steps there, it created a key successfully AND when opening seahorse again... the old key was discovered too!
I've attached a screenshot of this too - the highlighted one is the new one and I've censored the email address from the new one because I don't want it being public.