This might be a pointless question, but wouldn’t Rigoletto realize that the sack Sparafucile gave him had a body smaller than the Duke’s?  I assume that Gilda is smaller in stature than the Duke, but then again it could a pointless observation.  Another question that I was thinking: When Marullo reveals himself as the stranger in the dark in front of Rigoletto’s home and he tells Rigoletto that the group is there for Ceprano’s wife, how does Rigoleto not realize that they are in front of his own home?  Does Ceprano live close to Rigoletto?  Would courtiers live in homes like those of the court jester?