The jack itself is unique. And like most things associated with the Henry J, it was cheap and not that rugged. Here's what the original HJ jack looks like -
Here's for the trunk lid model from the owner's manual-
Strangely enough, the '51 and '52 Henry J owner's manuals (which are actually fold-out pamphlets) do not even show how the spare mounts or how to access it.
The Oct 1, 1950 issue of KF Dealer News shows only this picture -no jack visible which is why I just slide my jack over behind the tire.
The tire does have a J-bolt which hooks into the side of the trunk and a retainer with a large bolt on it to hold the tire in place. From all the info I have (Owner's Manual and Shop Manual) the jack just lays in there - no mounting hardware or methods shown or listed.
Here's the non-trunk model straight from the factory shop manual.
Since the jack is not visible, I concluded it is tucked over behind the tire.
Anyone else have any comments/info?