Spur Identification

With a little web sleuthing, I'm pretty sure I've narrowed the spur line down to the Zone 3 of the Frisco RR's Kansas City Terminal.  I signed up on the Frisco.org and hope that I can get final confirmation of the line's history there.  Additionally, I discovered at least one Sanborn Map of the area from the Kansas City Public Library Missouri Valley Collection -- though due to copyright restrictions, I can't post it here.