Glow-worm hideaway 80 FF - need repacement flue?

My father-in-law's boiler (3 year old Glow-worm Hideaway 80 fanned flue) has recently suffered some damage to the external part of the flue following a recent tree collapse. The boiler has been switched-off since the damage but we want to replace the flue. I know this model is now discontinued but I seem to recall the flues are still being made for other Glow-worm boilers. Can you please tell us what we need?