Coupe inside door lock

[raprice]

Gentlemen(and ladies)
I own a '30 coupe and can't figure out how to get the inside door lock to work on the driver's side. The door handle works, the inside latch works to open the door.
How do I access the inside of the door to add the necessary parts to help the sliding door lock work. The sliding latch works, but it doesn't have anything to latch onto.
How do I correct this situation? I hope my description is clear.
All the best,
Rog