78 300D linkage and idle adjust questions

[peragro]

Hi everyone;
I was tinkering on the new to me 300D yesterday trying to smooth out the rough idle a bit. It is a little smoother now then before after I lubed up the linkage points, but it still needs some work like fuel filter changes and valve adjustments - linkage adjustments too probably.

I have a sneaking suspicion that I'm missing some of my linkage pieces. Does anyone have a picture of what a complete one looks like on the 1978 300D? I'm also wondering what the compatibility of linkages off of later model cars are. I found an 80 D and and 82 SD at the junkyard today with what looked like similar linkages. Would these work?

Finally, my idle adjustment cable is completly shot. There is no longer an end for it to attach to the throttle linkage. I pulled the cable through into the passenger compartment but can't figure out how to get the cable off of the actual keylike knob. I don't want to break anything more by forcing the issue and didn't really turn up anything on the search, which is where I've been spending my evening. BTW, does the idle adjustment cable and the cruise control cable occupy the same space on the linkage? This is where that picture of a complete working linkage would be real handy if anyone has one -Please....