Quote Originally Posted by YALE7750 View Post
Here is the mortise lock, cylinders, and closeup of the maker's imprint on the deadbolt. This is a double cylinder lock with no stop buttons on the edge, and a latch bolt that is not reversible. I've never seen one like this before now. The keyway looks like it would be double-sided, but I cannot be sure since I've never seen a cut key for this lock. Compared to the typical Norwalk locks I know about, this is truly an oddball.
I've seen similar vintage locksets (not Norwalk) installed upside down since the anti-friction latch was not reversible!

Pete Schifferli