FWIW - I am currently reading the combined "Development of Aircraft Engines" by Robert Schlaifer and "Development of Aviation Fuels" by S. D. Heron, "Two Studies of Relations Between Government and Business", published by the Division of Research, Graduate School of Business Administration, Harvard University in 1950. So...? Well, on page 273 while discussing that the replacement for the Continental O-1430 needed to be a larger vee engine for fighters is the statement below:
"... but the tactical officers of the Air Corps had become convinced that they wanted an inverted vee for improved visibility," with the footnote #11 following
Footnote 11 on that page says:
"The decision to use inverted rather than upright vees was largely if not entirely due to Colonel Charles A. Lindbergh, who held no active position in the Army. Lindbergh had recently inspected the new German airplanes and had been much impressed especially by flying the Messerschmitt Me 109, which had and inverted-vee Daimler-Benz 601 engine. Continental would have preferred an upright vee both because it believed it easier to install and because it would have been easily interchangeable with the Allison in airframes designed for that engine, but the top authorities of the Air Corps insisted absolutely on an inverted engine."
I don't know the exact source of the info in this footnote by Robert Schfaifer, who is listed as an Assistant Professor of Business Administration at Harvard University. Just thought I would share. Yes, I have somewhat odd taste in reading

Randy