Kubert's pencils and inks credits from Julius Schwartz's editorial records, provided to the GCD by DC Comics.
The title is "The Invisible Viking!", but in fact Jon is shrunken.
No circulation figures are given.
Part 1 of story.
1) Part 2 of story. 2) Last appearance of the Silent Knight in The Brave and the Bold. He appeared occasionally in later DC stories. 3) The Silent Knight was ret-conned to be Brian KENT, a distant ancestor of Clark Kent. And he was ret-conned as one incarnation of Hawkman because of his hawk emblem. Thus Superman and Hawkman share a common ancestor.