Servicing question

[thegingerninja]

The CSL is due a service now based on time (2 years) rather than mileage.
Previous services were:-
- 02.04.2012 29,117 miles Inspection 2
- 29.05.2015 31,392 miles (accidentally let that lapse by one year) Oil service.

Current mileage 31,851

BMW are saying that the car now needs an inspection 1, which is a lumpy £ 684.46.

Am I in a position to say that the car doesn't need the valve clearances do not need checking on this occasion and can they adjust the service cost accordingly, since the car has only done 2,734 miles since the last time they were checked?

Also - did I read somewhere that BMW offer 50% discounted servicing costs on cars that are more than 10 years old, or was that a one time offer?

I'd like to keep the serving as it should be to keep good provenance on the car, so I'll probably end up just biting the bullet and having it done - just thought I'd ask if anyone else has got around this?

One other thing to add in - I no longer have the BMW warranty.