Vrs clutch change

My clutch has started slipping. 

It's only done about 30k miles and is currently a smf conversion (valeo 4p kit).

it seems somewhat intermittent being worse once warmed up. 

I tried to make it slip from cold this morning and it wouldn't but once warmed up it was easy to do. 

Power wise the car is totally standard. 

I know nothing about clutches but from a little research suspect it may be contamination from a leaking seal. 

I just had a look and there  is some oil on the bottom of the gearbox casing/engine block joint. 

It tends to need topping up about 500ml in a year but doesn't drip as there are no oil spots on the drive.  

The car is booked in for a week on Monday and just want to know if there are any parts worth replacing while the gearbox is off and the clutch/seal is being done. 

Is is it worth getting seals done anyway and the slave cylinder as I understand that's a gearbox off job too?

id rather spend £100 I might not need to rather than have to spend loads on labour another time. 

Cheers 

Edited 7 July, 20187 yr by sheb