Well, the fullness of time didn't take long; about 15 minutes in fact.
Mine is an APAC No 17, which apears to have come in both orange and grey and in two styles. The type I have has an enclosed cage hook on the base for moving the jack about. The model with no cage hook has the access hole rotated 15 degrees to the winding hole. In operation, this would have the effect of capturing the square nut at the end of the winder once the winder is withdrawn enabling withdrawral of the jack from beneath the car by pulling on the handle.
According to the Clyde-APAC company history
https://clydeapac.com.au/wordpress/wp-content/uploads/pdf/Company-Information-Clyde.pdf APAC made jacks for Holden for over 60 years. It also appears from a newspapaer article dated 16 December 1948 (found in the APAC history) that they provided the jacks for the FX. It is highly likely that the jacks without cage hooks are APAC No 17s as APAC were based in SA. In addition to their own jacks they made Lightburn hydraulic jacks both here and in South Africa. In 1954 APAC industries was acquired by Clyde Engineering in NSW and became Clyde APAC. From other articles I found at Ozwrenches
https://www.ozwrenches.com/jacks.htm#aussie APAC and Clyde APAC also supplied aftermarket jacks to NASCO.
Wylie were also based in SA and the Ozwrenches site has linked them as a supplier to Holden as well. On this site they show Wylie scissor jacks; the winding type for FE/FC and the ratcheting type for FB/EK.
This clearly shows the Holden had at least two jack suppliers. It is likely that APAC supplied the early bottle jacks and Wylie provided scissors. Given the APAC No 17 came in two styles I expect that the cage hook would be cheaper to manufacture than the capture mechanism inside the winder gear itself so I'm speculating that the jacks with the cage hook were the later version. I also expect that at some point it was found to be more economical to produce the bottle jack with a turned up tang style cage hook as opposed to the enclosed style on the jack I have. So my best guess is - FX/FJ capture mechanism in the winder, FJ/FE/FC enclosed cage hook, FC/EJ/EH tang style cage hook and then sometime down the track they went to a three stage bottle jack. Purely speculation - maybe the enclosed cage was for some other purpose/vehicle.
I'm not sure what records APAC have from back then but I'll write to them and see if I can't find out some more.
A deep dive into Holden jacks - I never would have thought it.