Rangemaster replacement – who actually made it?

We need to replace our Rangemaster 90 which is now broken.
We would probably go for the same again, as the size, style and set up suits us – it’s dual fuel as we have no gas on tap.
So two things:
In the Manufacturers’ section of the UKwhitegoods site, it indicates that they are sometimes outsourced to, e.g. Vestel. How can I find out whether the one we want to buy is genuine Rangemaster throughout, or has cheap and nasty components?
and:
We discovered only yesterday that our ‘brand new’ Rangemaster installed in 2008 was actually a 2001/2 model – which might be why parts are now unavailable. It may have been new, but it certainly wasn’t particuarly current and has only lasted 13 years rather than the 15-20 it’s claimed they should. How can we not get caught like this again?