Costly timing belt change

Hi, I bought a 2004 2.5 V6 petrol Freelander a couple of months ago and am thinking about changing the timing belt, so I got a couple of quotes. One was coming out at £492, and the other at £472. Given that I have just paid over £500 for a service and some parts, I am wondering if it is necessary to have this work done straight away? The Haynes manual states that it should be changed every 72k miles or 6 years. Given that my car has less than 54k on the clock, I am considering delaying the work by a few months. The only thing is that the Haynes manual only covers the 1.8, so I am wondering if the maintenance schedule is different for the 2.5? Does anyone know?
Thanks for reading.

P.S
I know that the 6 years are up anyway, but I figure that the miles you do are more important than how old the car is because I suppose that the timing belt doesn't wear out if the car is sitting in the garage?
P.P.S
if anyone knows a garage in SE London that doesn't rip you off too much, I would be keen to know.

Try here for info.

Freelander - Service and PDI (Pre Delivery Inspection) - Land Rover

The question is are you willing to risk the belt snapping and the costly engine damage that will result if you leave it. Such an event will cost you much more than £500, possibly righting off the car. Food for thought.

a guy i work with ,sold his car (renault) to another guy at work,
anyway before the new owner took delivery of the car , he arranged to have the timing belt relpaced by a garage, the mechanic collected the car from the guy selling the car and on the way to the garage the timing belt broke ,,,,, what are the odds of that happening,

getting back to your quiery, its not worth delaying the belt change, rubber ages, so its not just how many miles it had done that counts

More to the point, what was the luck of that happening? It wasn't broke when I gave to you mate!!

Thanks for your replies. I will get it done sooner rather than later then.
Can anyone recommend a mechanic in London that could do the work at a good price?