There is a huge post gap of around 3 years. Can you sign a message from old bitcoin address?
Though I can see Admin notes: Restored 2016-07-12. If you really want to get hold of your account, you can try this method.
Generate random password and change password. Log out & Delete passwords from history. Change the email too (Random)
I'm unable to sign from those addresses, as you mention 3 years ago is a long time for me to be out of the game.