What does "Restricted and additional lock up" mean on a security?

Yes, you are mainly right. A restricted stock cannot be sold on the open market, but the shares could be sold to another accredited investor, but such transactions are rare and virtually unattainable. Under Rule 144 of the SEC, restricted stock cannot be sold for at least 6 months after issuance, but if the stock holders (usually company insiders) agree to an additional lock up, that time to resell their restricted stock is extended to say 12 months or even 2 years before they can be sold to the public at large.