Ford used sodium soap mixed with gear oil. Sodium soap is still available as drum brake wheel bearing grease. A person can use that and make a slurry of the stuff to put in there. It's not thixotropic but it was all they had in that era.
The John Deere stuff may not be available in all the far reaches from the USA so you use what you can source locally. The NLGI rating is #0 grade in all the specifications I have read for the JD corn head grease and there is only one type. A grease gun is used to get the stuff into the intended component. There are other thixotropic greases & brand names and not all are the same. The JD grease thickens as soon as motion stops. It turns to the consistancy of gear oil anytime it's in motion. It's rated for temps as high as 335 degrees F or 165 C.
https://www.google.com/search?source...4dUDCAk&uact=5
The stuff works OK in south Texas and it gets pretty hot here in August through early October.