Modified D&RGW drop gondola *LINK* *PIC*

After operating a circa 1930’s D&RGW work extra this past weekend (1: 48 scale) a question regarding prototype practice for distributing ballast material ensued. Jim Holmes remembered that the GLRR when originally being constructed with help from the Seabees had converted a D&RGW drop bottom gondola to dump the load in the center of the car (vs. the outside as originally configured).
Does any of the former GLRR crew recall if this modified car still exists (and where is it now) and how effective was its use in this application. A search of Dave Dye’s remaining cars website (see link) showed the following cars at Silver Plume (prior to 2004) # 735, 767, 768, 824 (CHS), and 839 (which has a note about being sold to Universal Studios in Japan).
Rod
D&RGW # 767 Silver Plume, CO circa 2000 Dave Dye photo