TO THE BEST OF MY KNOWLEDGE the following is a complete list of plays acted in or directed by Dwain Johnson. "Complete" is a relative term, given that he was involved in numerous other productions as technical director and/or producer.
Some of the show histories are a bit murky. For example, Mr. J spoke so frequently about Merton of the Movies (1969) that I assumed he had directed it. However, after discovering the yearbook tribute page, I saw that Barb La Baw was listed as director. I now believe he likely served as technical director, as this production was the first to incorporate multimedia onstage--- a challenge I suspect he found exciting and rewarding. I have included it here because of the profound impact it had on him.
Another example is a Gustavus "project" that remains shrouded in mystery. It was a one-act play titled The Powers That Be. The script, which was tucked among his theater books, had been marked up as an actor would. It was in his handwriting. The play was a Samuel Beckett-esque one-act that was not included in Gustavus's formal listing of productions, nor do I recall Dwain ever mentioning it. My best guess is that it was either an entry in a one-act festival or a class project. I read it once before a catastrophic home fire destroyed the script. Sadly, I neglected to record the playwright and year. I have not listed it here.
Johnson's acting career didn't last long. After accompanying a college friend to an audition for A Connecticut Yankee In King Arthur's Court on a whim--- and getting cast as Merlin--- he caught the acting bug. He enthusiastically finished his time at Gustavus Adolphus College acting in numerous productions. Then as a high school theater director in 1957, he made an unplanned return to the stage when his young leading man was too sick to perform in The Imaginary Invalid, forcing Dwain to go onstage at the last minute. The next year, Dwain found himself at St. Cloud State University studying for his Master's Degree. While there, the bug hit again and he won the titular role in SCSU's production of Macbeth. Two more highly successful productions at Rochester Civic Theater followed but Johnson decided he wasn't a gifted actor. Although reviews disagreed, he never acted formally again.
The rest of his career he stuck to directing, teaching and producing. I'm confident that the Mayo history is complete as his secretary created a comprehensive list of his production there and gave it to him upon retirement. As always--- if you know of anything else that is neglected here, please get in touch.