Prod. UM48 - Mother Pluto
Animators that WERE assigned: Izzy Klein, Johnny Cannon, Bill Roberts, Norm Ferguson and Gerry Geronimi.
Note that the film is found on the Treasures DVD Silly Symphonies, while its production number shows it was part of the Mickey series...
[UPDATE: After the making of this draft, it was moved to the Silly Symphonies series and given prod. nr. US-38. Thanks, JB! Teaches me to check my sources!]