Assistance identifying mortise

I have an MI Windows Series 910 / V2000 sliding glass patio door. The interior thumb-operated locking slider became loose, and the hook latch barely moves when turning the actuator. I've removed the mortise lock and believe the internal mechanism has failed. The handle itself appears fine.

Thanks!
Measurements of the lock body, excluding the faceplate:

Length: approximately 102 mm (4 inches)
Width/thickness: approximately 12 mm (1/2 inch)
Mounting screw spacing: approximately 91 mm (center to center)

The lock has a single swinging hook. There are markings resembling a "V" near the top and an "A" near the bottom middle. Since the mechanism is broken, I can't determine the original actuator position.