Your tractor size(hp) will determine what class of 3pth comes on it. Most (probably all)CUT's all have the same size 3pth which is the same as the old 9ns and the old red 30hp Masseys. I believe its a class 2, simply because I have seen both larger and smaller hitches. I just don't remember if 1, or 3, is the larger or smaller...
The implement will have the hitch dimensions that are suitable for its class. While you can use implements that are designed for larger or smaller tractors, they will either not work to capacity or self destruct (sooner or later).
According to the manufacturers specifications your tractor comes with a Category I 3-point hitch. The mower should be the same. The above poster questioned whether your tactor is equipped with 3-point hitch linkage as you indicate that it is a TLB.
The original 3pt hitch for your tractor is definitely a Cat 1 hitch. That doesn't mean that the mower is Cat 1 though. If the pins on the mower are larger than 7/8" you can replace them with Cat 1 pins. The only problem that you may have then is that Cat 2 implements have a wider spacing and you will have to try that on your tractor to see if there is enough clearance.