Kuhn 4 basket tedder (old): model number location?

Hi All! Buying a used Kuhn 4 basket tedder. Year and model unknown, covered in gunk. Yup, it'll need parts and work but need the model number. Can you folks tell me where I find this on a Kuhn tedder? Thanks in advance.

 

For some context, we used to borrow a neighbor's old Walton (liked this!) But we've moved to a new farm in a new state and kinda need a new tedder.  We prefer the older beasties. Granted, we're not hay business just homestead/ small farm folk.

Kuhn 4 basket tedder (old): model number location?