Wow, thanks for the detail! I can't offer help. I replaced a rear side door mechanism because of a leaky lock actuator. I had to replace the mechanism because I can't figure out how to swap actuators. It looks like the hatch actuator doesn't come off on its own either.

My issue is I have to pull the hatch quickly. If I pull slowly, it hangs and closing assist pulls it closed. And the inside release lever hangs loose. So thanks for showing me how to get there.

Sixto
83 300SD
98 E320 wagon