Confirming the model year

If you are purchasing a used TM, how can you confirm the year that it was made? Is the production year machine stamped anywhere on the frame? Can you tell by the VIN? I'm about the purchase a used TM 3124KB from a dealer that doesn't normally carry TMs. Although I have no reason to believe they would try to deceive me, it's something I would like to verify. Thanks.

Kentwesley