“…god knows when and where”
I told you, Peter. Five ‘O’ levels would qualify you to apply for a short service commission in the RAF (and probably the other two services as well). I know this for sure because I was one such applicant (for aircrew, actually, because I had the required 2 ‘A’ Levels). I was successful but had to decline the offer for reasons that are too tedious to go into here. I had a similar income to you in 1968. It must have been the going rate.
I would suggest that a commission in the services is a “decent job” which would not be secured by five GCSE’s today. Those same qualifications would see you eligible to apply to the Civil Service for a “Clerical Officer” post. Two ‘A’ Levels would see you eligible to apply for “Executive Officer”. Most commercial concerns would make offers to people with five ‘O’ levels for various administrative positions. These were not brain surgeons or barristers but they provided the opening to a good career (provided the individual was prepared to work at it).
“Does anyone bother asking those who failed?”
In the year I took my 11+ just six (out of 35 in my class) passed. Not surprisingly, therefore I knew a number of friends who went to non-Grammar schools. I kept in touch with many of them and all seemed to have had a perfectly good education. They all seemed to be happy, none of them seemed to be harbouring any grudges against their grammar school chums. Most of them went on to “decent” jobs and one or two to very successful careers (far more successful than mine).
Where this model went wrong was that the standards of the non-grammar schools seemed to drop alarmingly somewhere in the late 60s/early 70s. The government’s response to this was not to try to raise their standards but to abolish the schools that were providing a good education. As I said earlier, because everybody cannot have the best, nobody can.