Not sure about Australia but for the US market those notes do not match changes in the US. All FJ25s thru 1960 had the four speed with single speed transfer case. Knob update was with the 68 model which started 9/67. 68 model had the amber reflectors on the front apron as well as the 69 model. 70-74 had a light on the aprron. 75 the side marker light was on the turn signal.
Unless Australia was completely different I'm seeing as many wrong dates as correct. 4.2 liter engine was 1/75 not 4/75 same with wiper location. Turn signal was also 1/75 not mid 74. New oil system was all 74 models not a mid year change. Three to four speed was a mid 74 change along with rear license plate bracket that changed to a two lamp design. 4/75 was the date of the gear change in the transfer case. Dual vacuum booster for the brakes changed with the 76 model and disc brakes on the front axle later in 75. That's only looking at a few pages.