Thanks to friend Katie Kiefer of Steamboat Springs, Colorado, the question is answered.
“Sunshine Cliff” ought to have struck more than a chord of sympathy with me, especially given the connection with the Twin Cities and their rich heritage of Arts & Crafts activities. This house appeared in the pages of The Minnesotan, a short-lived forum for the Arts & Crafts Movement edited by Maurice Flagg in Minneapolis and closely connected with the Minnesota State Arts Board. I saw issues of it while I was a grad student at the University of Texas at Austin (of all places, since in their view, if it isn’t in Texas, it’s crap). You can read more about Mary Garner McIntosh’s “Sunshine Cliff” and other characters in the Twin Cities at that time in an article from Minnesota History that Katie forwarded to me.
Incidentally, with an address now in hand, I went to google.earth and learned “Sunshine Cliff” has been replaced by something far less interesting.