I wrote this down months ago in my MB notes folder and couldn't even tell you where it's from or if it's 100% accurate:
"...early 70's Plymouth and Plymouth Grand Fury climate control servo fits 70's -80 116 &123 Mercedes..."
I've never dealt with this infamous Satanic (apparently) device, but maybe someone with more knowledge could hunt down some old NOS parts thru Plymouth (defunct) parts supplier. FWIW
The Golden Rule
1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)