How old were you when you left ? Could have been 16 or 18 years, this is what I find difficult about another site mostly. Would seem you could have been born in 1943 same as me, and my brother possibly a year older than your brother, but he left Accy Grammar at 18 .. he was born in 1939 .. May 3rd actually, (Happy Birthday dear brother in 15 mins time!).
BUT, your brother may have left at 16 years so could be 58 or 55 .. get my meaning, very difficult when people don't put their age in their profile (can't get away from it anyway). So come on spill the beans, sure I knew some of the lads that went to the Grammar then ...
I left Accy High in 1960 at 17 years.