I still see a lot of my Primary school friends around town and a few from the secondary. The Secondary did have separate School for boys and girls but Grammar was mixed.
The advantage of the Secondary school was its very new buildings to learn in while the Grammar was Victorian.
What is noticeable was that the Secondary boys leaving at aged 15, many became business owners by the age of about 22 and one in my class owned a huge company called Stovax. Another owned a large hotel and another was an International salesman owning spectacular cars while another became an owner of a 6 trawler fleet.One became Chef for the Queen Mother at her London house, Clarence. Our Grammar freinds mostly got good jobs but not many owning large businesses.
One of my Grammar freinds died last year of motor neurone in Romania where he lived after early retirement from working in Saudi in Architecture and he did became a Millionaire early on. Lost a few of these school mates lately. One keep fit man out on a bicycle just dropped dead and fell off aged 57 and another had cancer. I suppose a few more died that i have not known about but the Primary school classes that left in 1965 seemed to do very well.
The ones that went to work in banks, mostly got pensioned off as they reached 50 but they had good payouts.
I liked my old Schools and the Primary was a Church school so singing and church were a weekly event. Of course, when i was 5, i was at Sunday school then onto being in a church choir but i was not very interested in religion all that time