We recently purchased a home in rural Kentucky.
We have begun to move years of wallpaper and the cardboard base from the walls and have found numerous nails underneath.
We don't mind the horizontal wood pattern and would like to paint/stain it, but the question is "How to remove the nails or do you?"

There is no room to drywall the walls as the baseboards were set to the cardboard. To do this would be large and expensive...an unnecessary cost.