The EXTERIOR door handles/lock cylinder assemblies on my 81 300D (W123) are identical. Of course, the car has no alarm sys.
I moved door handle/lock cylinder assembly from driver side to pass. side & vice versa. Not only does this provide little-used lock cylinder to the driver side, but by flipping the handles up-side-down in the process, it also exposes un-weathered chrome to top side that had been previously protected for all those years on the underside on the handles. Not only do the locks/handles work nicely, they look like new, too.