So I adjusted as many of the linkages as possible using the FSM as a guide. I will document this further elsewhere, but it turns out that the lengths specified at the beginning of the chapter did not accomplish their necessary tasks, so I had to adjust a few on the fly. For instance, the "tickler" pull rod linkage ( from the lever on top of the valve cover down to the injection pump) is specified at 205 mm, ball to ball distance. But this length did not allow the IP tickler to be all the way down at idle. So made it as absolutely long as possible, and the tickler is now very close to all the way down at idle.

The absolutely AMAZING thing is that my loping, hunting, searching idle is GONE. YES! I honestly don't know how or why. I did a few other things to the car since it last ran, but nothing that would affect the idle. So I think adjusting the linkages correctly may have actually done it.

Regarding the semi-unobtanium MB reference gauge, here is my plan. I want to make a Solidworks solid model (a fancy name for a computer drawing) of all the 220D linkages from the throttle pedal, IP, intake butterfly valve, transmission, etc. and I think that I will be able to back-track the dimensions of this tool. I think I now know the constraints, but the geometry is too hard for me to deal with by hand. So I have no idea when I will have the time to do this, and there may be only two people on the planet that would care about the results, but this is my plan. Don't hold your breath though.