Unfortunately, I don't have any posted signed messages at all 
Is there another way to show I am the owner of the account?
All posts are in English
I don't think I ever posted in Local
Is there another way to show I am the owner of the account?
All posts are in English
I don't think I ever posted in Local
Its not necessary to have posted a signed message, a bitcoin address is enough. If you posted an address before with the account you are selling then you can probably provide a signed message