The Tree of Young Dreamers

Brought up in the Depression, Johnny DaSilva is leader of a fun and imaginative gang that lives out their dreams in the Big Tree in which each has a branch that serves as the Lone Ranger's Silver, the race car of Morey Amsterdam, the rocket ship of Buck Rogers, the crow's nest for Black Bart the Pirate.
When World War II broke out, they tried every ruse their young imaginations could think of to get into the marines, army, and navy but had to settle for the Boy Scouts. But the faux pas war to end all wars came too soon for the Big Tree Gang.
Johnny is best described by an aunt as having the millstone around the neck of having a strict English Episcopalian conscience and bucking bronco Portuguese sexual proclivities.
Two girls are in love with him, one wealthy and popular, the other sexually abused and who considered herself a worthless toy, until she met Johnny.
Whatever they knew about the facts of life, male and female, were learned pretty much by trial and error.