RK55H manufacture date?

[Annemkat]

Heli! We bought a (used) RK55 tractor recently - low hours, great shape, amazing price. We were told that it was a "2018, maybe a 2019", but it was taken in as credit towards a newer tractor and they didn't know for sure. Rural King has been no help tracking down the year from the serial number. BUT - looking over the tractor with a fine tooth comb to find anything we can date code I realized that the back tires are date coded 8/21, and the front ones are 7/21. Which leads me to believe that the machine might be a late '21 model, or early '22. The serial number is 55NHR00211. Anyone have any guesses what year it might be?