The 3 speed column shift trans was a B series option pretty much up untill the end of the 1200 model run, .......... in Japan

Vehicles for Australia were ordered by the state distributors through Nissan Australia & it was the state distributors that determined what they believed would sell well in their various states [or Territories]

In NSW, for instance, Capitol Motors ordered the 3 speed in the 1967 model range while in Victoria, it would seem that the state distributor ordered the 4 speed version for the 1967 model range.

Capitol Motors realised their mistake & discontinued the 3 speed when they ordered the new 1968 models, ... & the 3 speed was never seen again.

Both the 3 & 4 speed used the same trans case but with different sandwich plates & extention housings.
Even the 5 speed used the same basic case although in the revised [56A series] form.
The trans case always held 4 gears, either 3 forward plus reverse, or four forward with reverse in the extention housing, or 2nd to 5th in the case with 1st & reverse in the extention housing

The auto trans became available in the 1969 DeLuxe model, but not the Standard in Vic & NSW.
I have no idea what was available in the other states but this is how it seems to have gone in these two states.

As for the KB10, it was available in Australia only in the DeLuxe form & only with the 4 speed while the higher spec KB10GL in Japan could be ordered with the floor shift auto trans.