Bottom end for Winchester but top end against the national average for the 80s and 90s.Winchester is just under £34k per child for day students.
A GP could earn the equivalent of £100k/year if they did out of hours visits to patients homes etc.
A Pharmacist with their own practive would be earning at least £60K-£70k in the SE of England in todays money.
The school fees would take up about 55% of their disposable income at todays prices. I suspect there would have be few luxuries in the household and no holidays.
In the last 30 years private school fees have risen faster than salaries, so it would have been a bit easier then the finance the fees.
His parents would have been at the bottom end of incomes for Winchester children.
170k in 1990 is the equivalent of 376k pa in 2022