Well it looks like I have run into a stone wall with M-B!
Unless one is prepared to purchase either:
(1) a major transmission rebuild kit, or
(2) a complete new “valve body” [aka “shift housing”]
it does not appear that M-B is much help to me in my quest to try to come up with my own low cost K-1 kit for these earlier trannies.
Yes, I know some of you are saying that “I told you so” !

So this leaves me one final gasp to save my K-1 kit idea and this is based upon a suggestion by “C32AMG” who must have nightmares about these auto trannies or maybe he just worked most of his adult life in or owned a transmission shop and worked on a lot of these early trannies.

In any event, as soon as I finish working on another family car and make room in the garage, I will be dropping the pan on the 1980 300D’s tranny and remove the 3 springs and piston that make up what I now believe are collectively referred to as the “Accumulator ” section of the tranny’s
“Upper Body ”. This is reachable just by dropping the pan.

Once I have removed the 3 springs and piston, I will side-by-side compare them to those in M-B’s K-1 kit for the 722.3/722.4 trannies.
At that point I will have to decide on whether to install one or more of these updated springs in the my 722.118 tranny! So I will put it back together, fire her up and take it for a ride!

Of course I will report back to all of you who wait with "baited breath" or maybe more likely by now wishing I’d put this dead horse out of its pain!
Regards,
Sam