Check out Fastlane - Body Mechanical & Trim. The knobs are very inexpensive. Phil at the PartsShop can also get MB originals ( still cheap ). Recently replaced left switch with a used part from a 300E and still waiting for headrest knobs from Phil. I donot believe that straight 190E's have the position memory option.

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'87 190E 2.3-16
Heated Seats, Graphite Dash,
Delsing shift bushings