Interesting

It seems like this little film was the last time the Xerox machine was used at Disney:

http://www.ultimatedisney.com/101dalmatians-junket-414.html

"Up next was the camera room where the Xerox machine was demonstrated -- a device that ultimately saved Disney animation with its efficiency and cost-effectiveness. Developed by innovator Ub Iwerks in conjunction with the Xerox Corporation, the device was created to mechanically transfer artists' original drawings directly onto the final cell. Five people in three rooms ran the machine in its day. The selenium plates they use in the process can no longer be manufactured, so they're left with a limited few, though they do take good care of them. To compensate for differences in artist style, the exposure could be altered in the darkroom if the lines were lighter than the other drawings, for instance. The last film to use this process was 1990's The Prince and the Pauper."