Anderson Sliding Door latch replacement

It sounds like you may be referring to our 82-043 Andersen tribeca thumb latch. However, I can't be sure if this is what you're referring to without seeing photos of your hardware. If you can reply back to us showing some photos of the pieces you're referring to, I am sure we will have more answers for you. 

Thank you for getting back to us with your photos. Your lock does look like our 82-043 and 82-037. If it has been a great deal of time since these parts were first installed, you may want to consider replacing both pieces at the same time. Both pieces mentioned will work with each other. Have another look and let us know what you think. 

These look like the same photos as uploaded by the customer from Massachusetts earlier in this thread. We had recommended the 82-037 Andersen brand mortise lock for them. Have you reviewed this part yet? We still think it's our best match.