Technically, Baron doesn't have to sign anywhere. While verbal contracts are enforceable, it's unclear whether all the specific terms have been agreed to. Even if they were, legally all contracts for more than a year have to be in writing, and generally a court won't enforce them; this is something known as the "statute of frauds".
As a practical matter, though, I think both Baron and his agent would be black-listed if they attempted to back out of the contract at this point.