the problem is, the magnesium has a zinc di-chromate coating on it, you machine the venting into it and you will have to remove the window and the crank end bush to get it replated. if you don't the mag will absorb moisture from the atmosphere and corrode.
also, the tecmoto ones have the new type logo, not era specific to our models.
p.p.s, the one on e-bay looks like it suits the testastretta, different to the desmoquattro.
[Edited on 2-12-2005 by loony888]
[Edited on 2-12-2005 by loony888]