Nice set of images Izzie. I too like the mono but I would raise the shadows slightly and brighten the sky slightly as has already been suggested. Pushing up the exposure a little might be all you need. When it comes to distortion, the Warp tool is the hardest to use effectively. I prefer to use a combination of the other Transform tools so for instance for the Barn end:
1. Slight rotation to level the horizontals.
2. Use the
Perspective tool to correct the verticals by pulling out the bottom handles until the RHS is vertically correct. The LHS is still slightly leaning but see below.
3. Use the
Distortion tool by pulling down the bottom centre handle to stretch the barn and correct for height. You don't need all of the FG and it also makes more of the tyre tracks as a lead in.
4. Still using the
Distortion tool, pull out the top LHS handle slightly to finally correct the verticals on that side.
5. Crop - you may not wish to.
6. Select the sky and use the Highlights/Shadows tool to bring back some detail in the sky.
I have also lifted the shadows inside of the barn so that it takes your eye through to the rear door.
Just my take on the image and how I would go about correcting any distortion. Others may do it differently but I hope it helps.