Spoken with Past Parts here in Bury St Edmunds and they can reline the cylinder and fit new seals with a fast turnaround
Im guessing for warranty and consistency one fix from factory and only that will do
That's definitely what I'd do for a one off repair, but factor in 1200+ units (and those that are currently awaiting sale in dealerships and in production at the factory). plus the time for delivery there and back from all over UK and Europe, it will probably be far quicker to just whip out the old and stick in a new.