British Citizenship by Double Descent

[frustratedZA]

Hi All

After much reading and research and reading case studies, I've once again come to the conclusion that I do not qualify for British Citizenship.

I just thought I'd post here in any case, on the off-chance that someone had a smart idea or some little-known piece of information that I've overlooked that might lead to me becoming a British citizen.

--I was born in South Africa in 1992.
--My father was born in Iran in 1960.
--My father is British by descent.
--His father (my grandfather) was born in the UK.
--The only reason my father was born in Iran is because his father was there on a two-year work contract with British Petroleum.
--As far as I know - my father's birth was never actually registered in Iran and he does not have Iranian citizenship.
His birth was registered in the UK upon his family's return there.
--My father was educated in the UK and lived there for 20-odd years.

For a few years in my teens I would periodically check to see if the laws had changed and that I somehow qualified.
I then discovered a few days ago that the law changed in Jan 2010 to allow people under the age of 18 with a British-by-descent parent (who lived in the UK for at least two years) and British-born grandparent to register as British citizens.
I missed this 6-month window of opportunity unknowingly (I turned 18 in June 2010). How very frustrating.

I've come to the conclusion that an Ancestry Visa is my only route to (eventual) citizenship.

Any thoughts, or is my conclusion correct?