I've done some digging on this and drawn a blank. 

Watching Classic Corrie as I do, I've seen many an old bus in the background. 
However, when watching an episode recently, I spotted what looks like an ECW Atlantean on 'Rosamund St', as Ken Barlow was walking towards the cafe. 

Knowing the episode was shown in 1993 originally and the GAG ECW Atlantean's disappearing not too long prior to this, I was wondering if the white example in the photo was one of the native examples, living an extended life. 

I've checked online and can't find any white examples photographed in the Manchester area - to rule my theory in or out.
However, that's not to say there's no photos of it. 

Any help would be appreciated