[cheshired5]

Update.
Popped over yesterday and fitted the new genuine Volvo pipe section which cost around £26 from FRF Swansea.
New hose clamps from Halfords (so they did get £1.60 out of this) to replace the single use oetiker clamps.

System pressure tested and left for 5 minutes with no coolant leak and no loss of pressure.
The original, "That will be £800 madam" issue is job done for under £30.