Fascinating story.
"My instructor was forever swatting me on the arm and telling me to get my eyes off the guages and take a look around."
Couldn't resist: "gauge" is spelled alphabetically, as in A, e, i, o, U. (Alternatively, "gage" is also correct.)
It is said that the trimotor needed three engines because of the drag introduced by the corrugated skin. Oookay, I can almost see that... or maybe just from the extra weight.