OK, lets see if I can help.
Lets say you went down to a new car dealer in September 2013 and bought a new 2014 car. Was it built in 2014. Nope, it was built sometime probably in the summer of 2013. But your title says 2014 model on it, and it has features that distinguishes it from a 2013 car of the same make and model.. Some of these features may be only cosmetic, like taillights and grill, but it WILL be different.
Now on to tractors. It is not unusual for a tractor to set on a dealers lot for a year or even more. AND it may not have ANY distinguishing features from the previous year or even 2 or 3 years. Many times tractors have absolutely no changes from year to year. There is not exactly a title for tractors, of course there is a serial number and a build date usually encoded in that number. But tractors are considered the model year of the year they are placed into service, regardless of the build date. This happens a LOT. Now to compare the car you bought in late 2013 and consider a 2014 model year, because of these distinguishing features that make it a 2014 model, even though it was placed into service in 2013. Do you see where I am going with this? It does not matter when the build date was on tractors because they do not change. What matters is the "placed in service date"
Now after I have said all of that. Sometimes there are changes from year to year, and sometimes there are new features, or fixes for problems. An example would be the 2014 Tier 4 final compliance that new tractors are having to meet. BUT thousands of Tier 4 Interim tractors are still on dealers lots across the country, and must be sold. They will be sold at some point, and be considered 2014 machines. In fact many members are busy buying them up so they do NOT get a Tier 4 final machine so they don't have to deal with the extra equipment installed on them to meet Tier 4 final specs. Also because Tier 4 interim machines are somewhat cheaper than Tier 4 Final machines.
Where there specific changes in the machine on the lot you drove and the one that was delivered? If so, I would ask for the one on the lot. Or did you get the one you test drove? Do you Know? In other words are you missing out on something you believed you payed for? If not, than you are just like thousands of other owners here that have machines that were placed in service one year, and the build date was another year. Tractors are not like cars, no title, no license, no registration. I truly hope this helped explain this and I hope you obtain satisfaction one way or another.