Ok, so here's the deal...
  I now have a 5-spoke C-box section rear wheel to match the front Magnesium Marchi I bought some time ago. 
 Thing is, the rear is from an ST2 - so two major stumbling blocks, 
 1) Axle diameters are different 
 2) New wheel is actually wider than the old. 
 Well I think I can work around both, for 1) I was going to replace the bearings with an inner size that matches my axle (17mm sounds right, have not measured yet) - however, the bearings that are still fitted are perfectly good so, I had the idea of fitting a sleve tube of some sort in the wheel, that again will match the axle size. 
 25mm ID for the existing bearings also rings a bell so, a 17mm ID tube with a 4mm wall thinckness was something along the lines I had in mind. 
 Good or bad idea - comments please (also on material)! 
 2) The rear wheel does not fit by a stingey 2mm, I'm using the existing sprocket carrier, so I know the drive side is not the problem - I've also measure that the distance between the wheel and caliper bracket needs to be the same so that the caliper will sit correctly - so - the only option open is to machine  2mm off the outside of the caliper bracket. 
 I just wanna check and see if there is any flaw in my thinking before I go down this path! 
 Time for a Stella I think 
  Cheers - Frank