Hello, Ralph.
This engine is like the daddy of the engine used for the combines. With the start of the JD 62 / L tractor series, the engines were made by Hercules. That is what is in the video. The first Hercs used were model NXA with a 3.000 inch bore. That started in about 1937 with the JD model 62 which soon became the L. Next followed the Herc mod NXB with a 3.250 inch bore. These engines had no provision for electric starter. The engine block and bell housing were separate pieces and bolted together.
When it was demonstrated the market was firm for a tractor this size, Deere designed the LA/ LI tractor. With greater expected production numbers, Deere went into production of their own motor. It was much on the same design as the NXA and NXB, but the bore was 3.500 inches and the block and bell housing were cast in one piece with an added electric starter mount in the top of the bell housing. The LA engine ran about 300 RPM faster (18xx rpm.) and with the larger cylinder bore offered 14.3 Horsepower. I am quite sure the JD engine is the one used in JD combines and possible some balers
Just as a side note, I do have one of these JD LA engines in my garage that is freshly rebuilt. I am lacking a manifold and carburetor, but hope to hear it fire up one day.
Charlie V..