SRS control unit location

Just bought a used 1988 190E 2.3. It was in an accident (previous owner did tell me) and the airbag deployed. The airbag was replaced, but not the SRS control unit. It apparently is a one-time use item like the airbag. I've located a used control unit in operable condition. However, I have no idea where it is located. Would appreciate some info on where this unit is so I can replace it when it arrives. I'm assuming it is a small "black box" type device that plugs into the wiring harness.

Thanks.

Bob