I did do ball point last. My favorite ball point is Zebra F301. It has minimal clumping and almost all of my sketchbooks are with that pen. It feels good in my hand and doesn’t cause cramping, maybe because it is so narrow on the barrel. It also looks similar to graphite on paper so that I can get a wide range of tone with it.
It's a lovely scene and very skillfully done. I would have continued the colour that you have given the distant trees right up to the edge on the right side.