Prieser makes (made) a figure set, "Adam & Eve" #16400, unpainted. They include men & women, and have seperate arms, legs & heads in different positions, so you can make them into just about any pose. (Cowboys nude probably looked just like bankers or doctors nude! Lawyers are probably something else!)
The nudes are taken care of by sanding and painting sunbathers with skin tone.
Imex made/makes "American History Series" sets. #513, chuck wagon & prairie schooner set and #514 civil war ambulance & munitions wagon set. Both sets include sitting figures, and the civil war figure hats could be cut down to eliminate the "military" look. These are 1/72 scale, but will look OK if not placed too close to 1/87 figs. Looking at them right now, the figs don't look any bigger than most of my HO figs, and the wagons are realls neat!!