Indeed, in this case you couldn't crop more without ruining the reflection which is an important part of the image.
I rather meant a different composition/framing at shooting time, when you (perhaps) try some more shots of the place. The crop afterwads can correct many things but only partially, i.e. I would rather doctor the take than the already done image. Still this one is a good one to me.
Nick - many thanks for such a comprehensive and generous response. I did a crop to get rid of the wall but decided it took too much off the main reflected image (with a very basic digital camera and equally basic software on my laptop, I didn't have much chance to doctor the picture much at all). I take your point, though, and might well play with the picture, and others I took on the same day.
Very good details and endless DoF on this image that really catches the "british look and feel", Len! And I can't tell you what it is exactly... perhaps the clouds, or the rhythm of the building, or all things together. Robin might not recognize the city. He would still recognize the land, I guess!
I only wished the reflection to be "complete", though I assume that this was virtually impossible, ey? Many times the municipal authorities don't care at all about the photographer. ;-)
But still, what about leaving that black part on the bottom right out of the image? Perhaps a turn to the left could achieve this and at the same time a less centered view of the place, including the whole building at the left and omitting the other one at the right?