TA22 brake master, factory single or tandem?

[ToyTA22]

I am curious as to what other TA22 owners have or had, as far as original brake master cylinder is single or tandem.
I have a single cylinder with proportioning valve on my 1974 model but original Australian Toyota manual shows disk brake TA22 should have tandem with proportioning valve. Only the TA10 & TA12 Carina, with drum front, use single master cylinder
in the manual.
I am curious if a prior owner has changed this because that was only available.
My car has brake warning wiring there as well, which makes me ask this question.

[73GTV]

The rare TA20 Model Celica was a 1400cc 2TB engine had the front drum brakes used a single cylinder if memory servers me right, since I once owned one in Japan. Maybe it was upgraded by the previous owner.

http://members.iinet.com.au/~stepho/