OK, it's only a $2 jack, but it turned out to be in great condition. I scraped off the petrified grease, soaked the thing in Blue Lightning, prepped it, sprayed on a couple of coats of appliance epoxy, and cooked it at about 170º for a couple of days. I'm assuming this is one of the earlier TT jacks, as the picture in the 1928 book shows a separate handle for the ones sold then.
That's a nice looking Model T car jack, not a TT truck jack.
Here's why I took this to be a TT jack.
The number on the handle is 3391.
The parts book shows that number on the TT jack handle. The jack in the picture looks like mine except for the separate handle.
The same page shows the T jack looking very different.
Can anybody explain why I have a T jack, and not TT? Is there a reference anyone can cite?
The TT jack is a bit heavier than a T jack. The 2343 ratchet jack shown is used on the later Model T's. The earlier cars used the screw jack that you painted.