"Superman's Mystery Masquerade"
It would appear that Superman has adopted a second secret identity, that of Chris Delbart. Even so it offers no protection, as Superman finds himself blackmailed by a scientist who has discovered his alternate identity.
"One of Our Imps is Missing"
The courts of ZRFFF, want Mister Mxyztplk back in his home dimension now. However, they are informed by one of their court officers, that a moratorium on dimension travel has been placed on all the residents of ZRFFF. So, bringing him in themselves is quite impossible. Officer Grflznk decides that there is only one remedy for this situation; he contacts Superman.
(Daniel Webster, George Washington and Abraham Lincoln are all animated constructs by Mister Mxyztplk)