Hi,
I'm not quite sure, if my information helps you, because in Europe, here we sell a little bit different units from American version of TYM tractors.
The most important think about the mover is, if it is original TYM production or some local production. TYM factory has two types of mower for T293 called TMB60SH (side discharge) and TMB60RH (rear discharge). It takes about 20 minutes to disconnect it if you have some experience. It's needed to remove pins from hydraulic cylinders, unscrew the front coupling point, remove pins from rear wheels and turn them to be able to drive with the mover out. Last think is just to disconnect driving shaft and hydraulic hoses.
But if you plan to buy the original TYM mover be careful about following troubles.
Because the frame of the tractor isn't so much under the ground, it is almost impossible to set the cutting high of mower to more than 5 cm. It is not much. Also the cutting unit isn't really made to cut high grass. My friend from US said that "it is just for a final trim".
Also we had a lot of problems with burning belts on our mowers. Finally we had to update them with new pulleys and belts to solve this problem.
Here in Europe our customers mostly buy German production mower called Matev. They invented their mover for the JCB 323 tractor (same machine as TYM T273) and it works really well. I think it's one of the best mower for TYM tractor, but price is logically double.
According to HST unit, I cannot tell you really sure, but the European version has the HST unit from TYM. But it doesn't mean it is the TYM construction. Most of the parts inside TYM tractors are based on Japanese production (comes from Kubota, Iseki, Yanmar a.s.o.) but they are produced by TYM or by their supplier's in Korea and China. But the fact is that the HST unit has just the TYM part number in parts catalogue.
Hope it help's and sorry for my English.