I agree with Salty... That isn't a M front bumper/nose cone. Looks aftermarket to me as well. I would see if it was wrecked also. Check the front of the radiator for damaged fins. If you have a lot of bent over fins, it means something large has struck the radiator. IF NO fins are bent over, means that he probably replaced the radiator sometime recently. You get some bent fins just from road debris, just a normal item.
Also, check the bottom of the front nose and see if all the plastic under body pieces are intact. I found mine were broken up and realized that I had purchased a damaged car.
Make sure you are purchasing a true M. Verify the VIN # and check the driver's door jam for the proper markings. I will see if I can get a good picture of mine and see if that helps. Can't post that till Mon though.
1997 E36 M3 - running stocker style right now...