After reading the article found in the LIBRARY at this site on identifying Jacks, I also was curious to identify my jacks since I have two of them.
I also have two different handles, one that is cast and another that is a hollow stamped steel style.
Now, I could very well have switched out either or both along the way because I was a real scrounger for "nicer looking parts" while I worked at a few different salvage yards, while many old Mustangs and Cougars were around for easy pickings. I actually was surprised that one of my jacks seems to be correct, it IS a fine threaded with a double pinch-weld "+" for lifting on the flip top. The one pictured in the article found in the Library did not appear to have the double "+" style lifting point, yet the one pictured above in this thread does seem to have it and looks pretty much like mine does, except mine does not look that horrible from being rusted.
The OTHER jack I have is very similar over all except it has two different levels to hold onto the pinch weld with, one is higher or taller than the other. It also differs in that there is only 1 way to align it into the pinch weld, unlike the other jack just mentioned. I will try uploading pictures later and see if I also find any other identifying features that are mentioned in the <Library> article. It is possible that the 2nd one is not even out of a 60's model Mustang, but it would be nice to I.D. it just the same.