Saving a nice old glass sliding door with broken lock

by LA
(San Jose, CA, USA)

Hi there - We recently moved into an old home which has an old glass sliding door in the patio with a broken lock (knob jammed and hard to rotate). The sliding door is otherwise in a good condition and we would hate to replace it just to fix the lock problem. We were not able to locate the door manufacturer as the labels were missing on the door. I made several trips to various Home Depot, Lowes locations and searched Amazon extensively but not able to find a lock that would match this type of locking mechanism. Fitting any other type of lock would require new drilling/cutting of metal part.

Can someone please guide us how to save this door? Please see attached the picture of the lock for reference. The size of the screw holes are 3-15/16".