Mr. G. is the drama teacher at Summer Heights High, and the boys worked on the mountain heights in summer. So, Mr. G. is Brokieish.
Mr. G. was also a tennis player, pretty well knowed in his day, 1858 - 1950.
He was a closeted gay, as were Ennis and Jack, thus Brokieish.
His name was Gustaf, same as Gustavo Santaolalla.
Thus, Mr. G. was doubly BrokieishHe also happened to be king of Sweden, Gustaf V.