Since I cannot offer a critique, I will enter it here.
An incredible find and well taken! I love the perspective and the depth/vanishing point through the windows in the back. You really did a great job of getting the lighting right for the walls, stairs, etc. while the light in the back is so strong. That was not easy to achieve.
It looks like the camera was at a slight angle as you can see by the edge of the stairs up front. I do not know it the whole place leans, but you can straighten it up a bit in Photoshop. I like even geometry in my work, and this one is only my opinion; but as you see the shadow of the railing on the right lines up perfectly with the edge of the photograph. While on the left there is some space to the left of the shadow. If it were mine, I would crop the left side to the edge of the shadow.
However, these are just suggestions as to what I would do if it were my work and everyone has their own taste. Having said all of that, the reason I have offered these comments is that it is a great work of art and very well done!
I love this shot. It's dark and dirty and grubby...but also you get a sense of an attainable lightness. There's a lovely balance, and yet, asymmetrical enough to keep your eye moving around the piece. I think it's a fantastic shot. I would not change a thing