The puma/jaguar from Creature Comforts (1989) is visible in the museum.
In an effort to get Gromit out of the house, the penguin plays very loud music. One tune is "How Much is That Doggie in the Window?" and another is "Tie a Yellow Ribbon Round the 'Ole Oaktree" which indicates that he's just been released from prison.
In one scene, Gromit is reading "The Republic" by Pluto. The actual author is Plato; Pluto is Mickey Mouse's dog.
When Gromit is reading the newspaper at the café, one of the headlines is "Dog Reads Paper".
Gromit's birthday is February 12, indicated by the circling of the number 12 on the calendar and the month only having 29 days (it is also leap year).
The rubber glove that Feathers uses to cover his head has only 4 fingers (as is common in animation) despite the fact that Wallace and all humans in other Wallace and Gromit films have 5 fingers on each hand.