I have helped one of the salesmen do this to his E320 Coupe. Ended up real nice. Big problem is getting the needles back on correctly, he ended up getting the speedo recalibrated, as he has a bit of a lead foot and wanted it to be very accurate. I would check into doing all of the gauges. This salesman was going to do just the speedo too, looked like crap that way. Problem would be that the ML55 gauges have the chrome trim around them, which is cool looking, don't know if you could buy just that part.