[Lynn Eades]

Jim, I am headed down the same track. (excuse the pun!)
There are two diameters of the commercial jack. I have both and plan to use the large one.
Other than the markings and part number the main difference is that the actuating lever that fits the original is rectangular in section and has a matching casting on the jack. the commercial style car jacks are operated with a round rod. these have of course, a matching actuating casting as part of the jack.
Like you, I can live with these differences until I trip over the original at a reasonable price.
I was hoping to borrow the hook parts, and get some copies cast. This hasn't happened yet.
I have been thinking of doing some mods to a ratchet strap (just the hook ends) to see how well they work. I know they are in common useage, ( un modified) with some carrier guys.
The plan is to substitute the standard hook with the hook from an Australian carrier track jack.