To restore or not?

I suppose you can look at the restoration of a painting in two different ways. The first being, don’t, it should be left just as it is. Let the painting speak for itself. The second being, bring the painting back to its former glory.
I think I come down on the side of leave it, but who am I to say which is right. I have seen sympathetically restored paintings, that have only needed a little work to help them and I have seen what I would say have been overly restored, where in my opinion too much has changed from the original painting, almost making it a new painting.
An Isherwood was sold through auction un-restored, and not long after, came back onto the market again, only this time it was restored.
Both images have been taken from the web, so colours cannot be guaranteed. You can make your own mind up as to what you think.

..un-restored1

 

 

restored1 .