The Midland Railway Centre is one of the homes for old trains undergoing refurbishment. More pictures of the train above can be found here. I love the idea that old locomative trains can get a make-over as a London Underground train.
Here's another carriage undergoing a makeover. You can see that most of its cab end has been replated. Known in the trade as LU Choppers, it's unlikely that you'll get to see them in London, but they'd certainly turn a few heads if they made it down here.
These "hybrid" Tube / Trains remind me of the Tube/ Bus/Train that was refurbished last year
Thanks to @julog90 for bringing this to my attention.