I've got for sale an LH fuel injection computer, MB part number 014 545 18 32, which DOES HAVE the WOT mode.
This computer was taken from a 1992 500SEL (W140), but it is functionally identical to the 1992 500E injection computers. Date of manufacture was March, 1992, as shown on the label.
Price is $133.90 + 16.10 shipping via US Priority Mail Medium Flat Rate Box, for a total of $150 shipped to your door.
This is plug and play in any E500E, and for 1993 and 1994 cars, will provide the additional 7-12 HP at WOT.