Bert Christman's last work on the strip was on 1938-06-xx, and Frank Robbins begins on 1939-05-22, with Howell Dodd handling the art chores during the intervening period. So, these reprints fall within that period, probably that immediately following Christman's departure.
Edmund Good was previously suggested as writer/artist, but his stint on the strip did not begin until 1944.
Seven unrelated panels giving various historical facts.
The strip ran between 1934-01-22 and 1938, so these reprints fall within that period.