18.75x23.75" onionskin sheet has original pen and ink watercolor art depicting concept design for Marx playset that eventually became the "Comanche Pass" playset #3416. ©1973 Schnur Appel Design Corp as stamped at lower right. Design features a military stockade fort situated on a mountaintop, complete w/"Dutchman Mine" feature and a partially visible sign above fort entrance that reads "Fort Cour..." which we assume to be "Fort Courage." The final design of the playset that came to be "Comanche Pass" differs somewhat as the stockade fort element was eliminated entirely in favor of a larger mountain w/caves design. Sheet has been rolled and shows wear w/some small .25" tears along top margin and 1" and .5x1" piece missing from bottom corners. If framed, the nicely detailed art would display Exc. Unique.