Rob
This is how the image came into ARC...
I did the usual tonal adjustments but in addition I reduced the saturation to obtain the final muted colours (I haven't done a screen grab for this).
In PS I used the Distort tool as shown here to correct verticals...
The problem with this is the distortion introduced by the wide lens which the distort tool hasn't fixed. This is apprent in the red ringed areas of the column. These bits make it obvious that the perspective is off. To correct these I used Lasso to create a feathered selection of each part and copied it to a new layer. I then used the Distort tool on each new layer to adjust the problems and added a layer mask to allow me to blend them back into the image. The final layers palette is like this...
Obviously other adjustments were needed such as using the Polygon selection around that large picture to create a masked levels adjustment layer to brighten it up.
I know this is all normal for you but others may find the info useful/interesting.
You made the point that the image didn't seem to be heavily processed (hate that expression BTW) which is rather a compliment because in my opinion good manipulation shouldn't be apparent to the viewer (thank God the days of badly burnt-in skies on mono prints is over!).
Regards
Les