2015 raptor vs 2016 raptor

I just bought a brand new hustler 42" raptor but I think the dealer pulled a fast one on me and sold me a new 2015 instead of a 2016. I wanted a 2016 and paid the same price for one but the mower I have appears to be a 2015 based on red "raptor" label on front and the serial number starts with a 15. Is there really any difference in the 2 year models? I am going to call the dealer in the morning but I would like to know if there really is any difference other than the stickers. I'm sure the value of a '16 is a little more than the '15 so if that is the case I may try to ask for some money back. The engine is a kohler and appears to be the same as 2016 models. I appreciate your thoughts.

What did dealer have to say?