Here's a new one:
"I Razick am the sole owner of the address 1vayZZw4U1pKQic2FjZ7aYg8e1qDSNxCC. Today's date is 6/9/2020."
Signature: HEstMca7FsXTTzIj8xgQmKA2dW4gtMGXb9+6iAizcDRwk8ytf+DCZUXWjdHIR1WNl5CIOFRwzaTDvpWJ2x/Doz4=
Exclude quotes to verify message. Bare Signature (QT Compatible).
Signature verified using Electrum

I also managed to verify it using Brainwallet:
Verified.
So this should be good for a start.