Scrooge & coffee

[Larry Giver]

Sigvald, Carl Barks wrote several half-page or one page
gags of Scrooge ordering a cup of coffee in a diner, trying to
get a lower price than normal or a larger portion.  In one
episode, he brings his own expanding cup; in another, he
brings his own donut, which is made of sponge material.
Don Rosa included both these items in scenes of Scrooge's
storeroom (I think early in the story when Donald starts
the shrinking-ray machine).