Garth, You discussed those cars with me (among others). John's pictures and info is stashed away at the moment, so out of reach. I also supplied you with copies of the Pullman drawings.
The last original -but renumbered- Pullman cars remaining on the WP roster were the 26001-26125 plaster cars and they stayed -in MW- until the end of WP in 1983. These were the last remaining cars on the roster, not the 8051-series tool cars. See the enclosed 1964 diagram.