cut out a piece of the top left wood planks and make it in to a new layer, free transform it, move it over the chair, take the opacity down, you'll have flip it(vert), rotate it and then skew it, till you get the different lines matched up. Once they match, add a layer mask and use the gradient tool to soften the edges, you can do the same with the white door frame, this one you might want to add some shadow with a dedicated curve layer as well.
This was a VERY quick edit:)
Awesome job, although it sounds like you're using 3 or 4 layers, and adjusting gradients. To me that would not be a "very quick edit"...but then I work slowly a lot of the time!
I could have done something with just the clone stamp tool and no layers...although it probably would not turn out very good.
I would just tone down the background, maybe apply a blur and some vignette, and forget about trying to remove the chair. The background doesn't really serve the portrait very well anyway. There are a lot of things that can be done, obviously.