This is the kind of portrait which is contextualized as the foreground and the background let us know where your dad was and what he was doing at the moment of the shot.
The background is not a brilliant one indeed because it is too noise,there is a door, a way out, a wall with lots of texture, some lights or so it seams, but ...
I am sorry that he is not looking to the other side or that there isn't more image on the right right (our right side) as he is looking this way. May be you could "darken" the background...
The "treatment" you imposed the image is not of my preference but that, as well as other aspects, is quite personal and if you like it... Fine.
Thank you for posting Peter.