To help bridge the continuity, until we find the missing issues, thanks to Steve Thompson, President of the Pogo Fan Club and author of the Walt Kelly Collector's Guide, I can offer the basic story lines for # 4, 5 and 6:
#4, no image at this time, 'the Hornets attack the grain wagons and dump flour during harvest time.'
#5, low-res cover shown below, 'the Wizard and Dragonel are chained by the little people, but plan to escape.'
#6, low-res cover shown below, 'the little people have a council of war, and Dragonel decides to spy.'
And we can pick up here with #7 in total, with nice scans thanks to OtherEric, with a little clean-up by me: