George Gray is the man on the ladder when the Stooges run from Mrs. Eggerley.
Johnny Kascier is seen getting on the train with the others, and appears in the berth with everyone else when the boys are getting escorted off the train by Laughton, Jamison and Morton.
Also in the berth: Bert Young and Charles Dorety. When everyone falls over in the berth, Bert is pretty much in the middle of the screen, while Charles appears WAAAY in the back when the boys are escorted. Both are also seen peeking their heads out (Bert out of the left, next to another; Charles to the right, putting hand to mouth and yawning) in the long shot of Pain calling for Johnson, right before the monkey crawls into his bed.
When Jamison/Johnson pulls the monkey (and the cord) towards the end, there is a woman's head in plain view who I think may be Elaine Waters?