Hi,
the motor itself will fit to all MX and LX tv sets, but not for MX8000 and MX4200.
There are 3 plates: LX, MX 28" and MX 21". So the MX5500 plate will fit to all 28" MX4500-5000-5500-6000-7000-8000.
The stand is more or less universal, it will fit to all modells. But i would not use the smaller MX3000 stand for a wide LX5500... There a some differences in hight, wide and the material. There is the old steel ST5000 and alumenum types 4106/4107.
Martin