Hi Adam,
23,000 is no mileage, unless you floor it all the time, I know that there is a conversion for the clutch master and slave but dont know if thats when the clutch wont work getting gears or for when it slips. I can not remember if its on here or on the XPF, Sheddist kit or something like it.
I think the master sits on the bulkhead and takes the first pressure when you push the clutch down and the slave is mounted on the gearbox and actually pushes the clutch plate in (or out) so that you disengage engine from gearbox so you can change gear.
Hope you get it sorted