I was torn between placing this here or in the Figures forum. I decided here because these would best be used in a diorama as opposed to stand alone.
The current Amazing Figure Modeller has an article where the author used some of the old Marx playset figures in his dinosaur diorama.
I happen to collect old playsets and never even thought of this!!!
I took a look at my collection and realized that indeed some (not all by any means) of these have as much detail as those in figure sets. These would be "about" 54mm or 1/32 scale.
Granted these would not be ideal but a variety of Cowboys, Indians, Frontiersmen, etc are sparse in the 1/24 to 1/35 scales.
These would best be used in a diorama where scale was not critical, like dinosaurs, monsters, aliens, etc.
Also not sure how they would work mixed with dedicated figure sets.
Anyway, its worth considering.