I sent mine to Turbo dynamics
How ever they more or less said... its dead, you need a full new unit,
Where as ive been told CR can work with slightly worse components or get hold of the parts to make good a poorly turbo.
Mine cost me around £1000 from them but it is their top spec item though,
I would contact Badger 5 he will point you in the right direction as he has probably seen more rebuilt or hybridised turbos than most members