Thought this photo might be of interest. It's taken at a film lot in 1966 during the making of Verity Lambert's Adam Adamant series starring Gerald Harper. I noticed in the background what looked like a Police Box prop in the scenery store. Not very accurate though, with the flat roof etc, but I suppose the white window frames are OK. Thought it might be the one used in the first Dalek movie, but I'm not sure now.
The roof is definitely on, but I think the angle of the camera (it's looking up from a height of 3 feet approx) would made a slightly sloped roof look flat from that angle, especially from that distance.
"My pilot's license? That's out back in the Cessna. Or perhaps you're referring to my license to kill. Revoked. Trouble at the Kazakhstan border. I could give you the details but then I'd have to kill you, which I can't do because my license to kill has been revoked."