There is a vast deal of difference between attending a state grammar school and being privately educated at a public school, though, so I'm struggling to see what you are expecting to get from this, OP.
I went to a grammar school in the 1970s, in Lincolnshire. It had, and still does have, the grammar system in parts of it. The fact that I was bright at 11 meant that I didn't go to the local secondary modern which stopped at 16 and simply aimed to train the less academic kids for practical, skilled jobs like being a plasterer or a builder. Kids at my school were offered the chance of A levels, but it wasn't a given that we would go to university - probably around 50% did. Probably about 20% left at 16 anyway - they were farmer's sons and would go onto the farm, or they had a dad in a trade and would go as his apprentice.
As a girl in the 1970s I was not encouraged to do anything scientific or engineering based. It's clear as I've aged that I am actually very practical - I'm good at DiY and woodwork, and although not good at maths or science I wonder how much of that is down to the fairly inadequate teaching I got. My teachers were poor - they were often staff who couldn't have coped in a rough school with difficult pupils. I certainly didn't get outstanding teaching and we had very little in the way of facilities.
In no way was this education the equivalent to having been sent to an outstanding boarding school where I was given advantages, teaching and opportunities that others did not have.
I would say, locally, that there is very little earning difference between the folks in my class at school and the others I went to primary school with who didn't pass the 11+. And I would suggest that we didn't have much of an advantage over them. Some of them joined the grammar at 16 to do their A levels, and some of my class left.
I went into education, by the way as I didn't have much clue what to do and no careers advice at all. Most of the girls of my age became teachers or nurses. It was considered 'suitable' for girls.