Cambelt or flywheel failure? (Skoda Octavia)

Skoda Octavia estate 1.9TDi PD Ambiente 130k.
I am hearing a low rattling sound when engine idles but otherwise runs smooth.
Garage tell me flywheel failure ((£700) but this is before I realised my wife's car had not had its cambelt changed since 2009 even though it has not done the required 70k miles since last changed. Could the noise be cambelt rather than flywheel? Anyway of telling? There are no other symptoms except I am sure I have experienced very occasional loss of power when trying to accelerate. There is no clutch vibration etc

Thanks in advance

Regardless of where the noise might be coming from, it is obvious that the Timing Belt (Cambelt) needs to be changed. If anything is making a noise in the area of the Timing Belt, I'd venture to say it is not the belt and more likely one of the components (idlers, rollers, Water Pump and/or tensioner). I'd do the TB change as soon as possible!

Thanks Andy Bees: I am kind of hoping that it may be the cambelt but am concerned that i will have to replace flywheel aswell which is uneconomical given age and value of car...that was the purpose of my question. However I realise I have to make a decision quickly.
Cheers

They are on opposite ends of the engine. Seems l like you could isolate to one side or the other.