First off,thanks for everyone that put something into helping me fix this,much appreciated.
Got the turbo from ECP in the end as it was a genuine new Garret unit.
I followed the fitting list to the letter. The oil filter was one big gooey black lump!
Took off the plastic inlet pipe,all the turbo pipes and intercooler and cleaned out the surplus oil.
After I refilled with oil but before putting the turbo/DPF back on I ran the engine briefly so I could check that oil came out of the feed hole in the block. Put it all back together and did the oil volume over 60 seconds and got 500 ml so within spec.
Unfortunately the car ran badly!
Several codes logged and the info display flashing block.
Took off the DPF and it was quite literally blocked with carbon.
Fitted a new DPF,cleared the codes and it ran very well.Did a further oil change at this point and let owner have it back.
Its been back with them 3 weeks and they tell me its running ok. I did put them off driving up to Cumbria from Reading!
I did go through with them before starting the work all the possibilities of engine damage and they were ok with this.
The only upside doing this job is that all the parts are accessable, a unique thing on a french car!
Hope this may help someone else.
Cheers,
Tony