If your tractor has a 17 character VIN, it's the 10th digit. I don't think Ford/NH used this format in the earlier years. If it starts with an H and not 17, it's older.
How many years did they make the TC30?
mornin. if ya go on tractordata.com and click on your tractor, it will tell you how to read your serial #. and will tell you a lot more also. hope this helps ya.