This afternoon, I was able to track down the KCS 4006 on the point of the QSHKC13. Here it is pulling north through the siding at Jaudon, MO, some 30 or so miles south of Kansas City.
This unit was just recently released from KCS' Shreveport, LA shops, and this was its first trip north after its repainting.
More info on the unit can be found here: http://www.kcsouthern.com/media/news/news-releases/kcs-veterans-day-salute-unveils-patriotic-locomotive-events-for-u-s-military-active-duty-and-veteran-employees