I like the conversion. The tones are very pleasant.
The composition needs to be toward the left a bit. There’s something intruding on the right hand window second from the top (an airplane wing?), and the shadows on the floor are forming a line leading my eye straight out of the frame.
Another option could be to crop just a tad off the right to remove that fleck, and crop off the bottom until just above the 3rd horizontal shadow from the bottom (counting the one that’s currently on the bottom as the first).
Unfortunately, that loses you the 4:3 aspect ratio, but oh well.