Ageing Hunter 6 double sided Multifuel stove

[Cliffclop]

Hi, 

I was thinking about changing my Hunter for a more modern stove, but given the prices, I'm having second thoughts, as there's nothing wrong with the stove, although it's been in about 17 years. I can refurbish it with new door rope and gaskets as they're still available.  My only concern is around the state of the flue. It's double skinned and is inside an existing chimney, it's swept once a year. and there's no evidence of anything wrong with it. The stove is used to burn mostly seasoned wood, with the odd load of smokeless anthracite, as a secondary heat source, along with oil.  Does the flue have a recommended life? any opinions would be appreciated.