After much research I was able to find the air-flow meter
potentiometer only (as opposed to the whole assembly)
for my 1986 190E 16V.

The two equivalent Bosch part numbers are 3437 224 035
and 3430 591 017 but part is the same. They fit both
1986 and 1987 16V models.

I can get the 3437 224 035 . If you are interested the cost
is $58.00 (shipping included within USA48)

Please reply ASAP.

Tony Ander
aander@newsignal.com