Re: hi
Chances are that it's a C514.
The C526 is the so called "wet shaft" gearbox fitted to some 1108s, but, AFAIK, no Sportings.
Easy way to tell, the C514 has a reverse detente on the gearlever (you have to pull up -- or push down -- can't remember which -- to get reverse), while the wet shaft C526, cursed be its name, does not.
You might consider buying parts from a specialist like eurocarcare in Derby or Shop4Parts, either of which will be able to match parts to VIN. You'll probably save a little money and a lot of hastle.
Google will find.
Having said all that, I'm pretty sure that the clutches on all 1108 cars are the same. The 899 ones are different, though.