Okay, I got this to work in my '92 190E! I bought
this Omega keyless entry module for roughly $30 shipped. I then had the seller send me a DLS-V ($18/shipped), which is a pair of relays wired together and designed to plug into the Omega module. Once the module and DLS-V are connected, there are only 4 wires to connect! Here are the instructions...
Here is what it looks like before you put it into the car...
This is so simple, it's scary! It worked the first time I tested it! I did have to adjust the module to send out a longer lasting signal.