It's a good find, thanks for posting it. I can't quite tell if that is the one with Aldrich (who was young enough to enter it) winning.
Brett
Air Trails, December 1951, published the winners from the 5th Plymouth International Model Airplane Contest. The Plymouth contests had different age brackets than what the AMA used and I do not know what the age categories were. For stunt:
Freshman: 1st - D.W. Alford, 2nd - Fred W. Sage, 3rd - Robert Leyner
Junior: 1st Gary L. DeVore, 2nd - Loyd W. Curtis, 3rd - Gerard Anderer
Senior: 1st - George M. Aldrich, 2nd - Don G. Joslin, 3rd - Harold Price
From Air Trails, December 1952, the 6th Plymouth meet, Stunt:
Freshman: 1st - Fred W. Sage, 2nd - Dennis W. Alford, 3rd - Chris A Hanson
Junior: 1st - Lloyd W. Curtis, 2nd - Bill Rood & C. Hill Hutchins, 3rd - Arthur P. Pawloski
Senior: 1st - James G Ebejer, 2nd - Donald E. Ferguson, 3rd - Gerald F. Wagner
In the 51 issue, there is a picture of a very young George Aldrich receiving his 1st place trophy. I saw that trophy in George's house in 1965.
Keith