Pulled the Blaupunkt head unit from my '84 280E. Don't think it's factory equipment, correct me if that's wrong, but it is at least period correct. All functions are working correctly except the right arrow button that seeks stations in one direction and I think fast forwards tapes as well. The arrow button for the other direction/rewinding works. I didn't do extensive testing before I pulled it and never tried to play a tape in it. The car it comes from has an immaculate interior and was more than well taken care of, so there's no reason for me to believe the same about the radio. Comes with the original forms, booklets, and instructions. Apparently these are popular with the Porsche enthusiasts as well, and some VW enthusiasts. PM me with any questions or for more pictures (i have a bunch but they won't upload). Have no idea what this is worth but i put in an e-mail to these guys:
Original radios for your classic car so maybe i'll find something out soon. PM an offer if you're interested. This will probably end up on e-bay next, especially if i find out how much it's worth.