Sliding patio door lock.

Hello there!

We appreciate you reaching out to us. I couldn't cross-reference the part number given here. Would it be possible for us to see some photos of the lock in question? You can upload them right here on this page or by emailing them to help@swisco.com with reference number D312381.

Our 82-265 mortise lock was the first to come to mind. However, I see that you purchased this already. Is the lock you purchased on the left in your photo? Can you clarify which is your original lock? 

Thank you! This reminds me of the lock that's included with the 82-402 lock set. Take a look at the specifications and see if they match what you need.

Unfortunately, we don't sell the mortise lock separately. I am very sorry for the inconvenience.

View of the mortise lock included with 82-402