It sounds fair and possible, the issue being if they find nothing and have to refit a new clutch for you, you pay the full fitted price.
I am not suggesting you have, but you could destroy a clutch in 14k miles if you treated it without sympathy.
I don't think you have much choice but to go down this route in the hope they find something.
I would point out the low wear on the tyres and overall fantastic condition of the car to show how well you have treated it over the last 14k miles and how likely it must be a manufacturing fault or leaking seal.
It;s not down to me obviously, but if you can show the rest of the car is such good condition, with a little goodwill, it may be a 50/50 decision.
Good luck.