Hi Swisco,
You guys are the best. Thank you for fantastic phone support last week. I am sending 4 photos of a sliding glass door assembly. The markings I found said "SASH CONTROL 1962 3" if I am reading them correctly.
I want to add a keyed lock to it. It doesn't matter if I have to buy a whole new assembly, as the client wants to be able to lock their patio.
High Fives to You All,
Gregg