Registration as a British Citizen - South African, born 1959

[amadlozi]

Background: I am a South African citizen, born in South Africa, in 1959, to a British mother ( British by birth herself ) . I was also a long term UK resident - with right to indefinite leave - from 1975 to 1986, but lost that right due to continued absence from the UK.
I have recently learned that "certain persons" born before 1983 may now claim British citizenship through decent from a British mother, an avenue that was not possible until a few years ago, apparently. I have read the Home Office's Guide UKM, and am unsure as to whether my circumstances satisfy the three requirements laid out in the document.

Could anybody with personal experience of similar circumstances, or particular knowledge on the topic, please offer some clarification?

[Amber]

You will be entitled to registration if:
●● you were born before 1 January 1983; and
●● you would have become a citizen of the United Kingdom and Colonies by descent if women had been able to pass on citizenship to their children in the same way as men at the time of your birth; and
●● had you become a citizen of the United Kingdom and Colonies, you would then have had the right of abode in the United Kingdom; and
●● the Secretary of State is satisfied that you are of good character.