There were a whole heap GYT bits for the DT1. Don't know how they relate to the "GYT kit" or the 'off the showroom floor' DT2MX, but the listing I've got shows: barrel, head, piston, carb, muffler, front rim and spokes, blanking plugs, etc.
Interestingly, the list for the DT1 GYT bits is much shorter than the list for AT1 and RT1 GYT bits.