If you really can't figure out what year your body is, look at the numbers. If I remember correctly, they made something like 5000 31 standard phaetons versus 16000 30 models. That gives you about a 75% chance of it being a 30. I believe the judging standard says something about the rear door latch being redesigned in late 30 to accept a third screw. If your rear doors were only held on with two screws, then for sure you have a 30. Either way, you have a far rarer car than the 59,000 29 models built.