BullnoseBob:
The first two threads are factory original jacks for the '60-'66 as indicated in the factory jack instructions that were adhered to the floor adjacent to the jack, handle and lug wrench mounting brackets under the driver's seat. The third thread is the same style jack, minus the jack saddle that is attached to the top of the jack stem for capturing axle tubes, king pins, frame rail and other shapes found under the truck.
I am restoring a '66, C-10 and '66, K-10 that were both minus the factory jack, lug wrench and handle. I knew what was provided from the factory from the factory jack illustrations, as well as the equipment that come in a '66 one owner that I bought in 1983. I acquired two original jacks and handles, but was unable to find the lug wrench. I also have the factory jack instructions. I you are interested in any of this equipment, e-mail me and I may be able to help you out.