Al, I think I may have seen the same 230SL. Was it on e-bay earlier this year being sold by a dealer in NY? I sent them a message asking about the year based on the VIN and they said they would get back to me but I never heard back.
Dave, to add further confusion, the model year also depends on whether your car is a US or Euro model. I have a 1966 230SL and it was made in mid October 1966 (45th birthday is coming up). Because it is a Euro car, it is registered as a 1966 and not a 1967, which would have been the case had the car been exported to the US.