the current state of things = partially fixed
So I put in the new engine shocks, just because it seemed like the last thing to do short of putting the used IP in that I just bought on Ebay for $50.
And, surprisingly, the shocks helped quite a bit. The side to side shaking at hot idle seems to have been significantly reduced. The car is not as smooth as my SDL, but it is now very drivable and not at all annoying at a stop light.
The old shocks were pretty "grindy" and were pretty easy to compress with my thumb (equals not much dampening power). I am thinking that once the engine warmed up enough, so did the shocks, and they ceased to work.
I will see if the problem returns over the next couple of weeks. Hopefully, I won't have to put that IP in just yet.
thanks for your help
84 300TD - 235k - Farbe "Surfblau" bought at 213k
87 300SDL - 131k - Farbe "PimpGold" bought at 115k
00 Klepper Faltboot Expedition Double