That was a neat video! I'm originally from snow country and had never heard of or saw that machine before. Interesting!!
From my research. Looks like the engine is a 820 west bend.
There was a lot of innovation back in the late '60s, early '70s. Hundreds of manufacturers, and often it was the successful business plan rather than the best innovations which survived. John Deere, Mercury, Evinrude, and Johnson all made sleds. The first two were likely the first liquid cooled. Bolens made a twin track with a sled pulled behind that you sat on. Bombardier and a company going by the name of Raider each manufactured twin tracked machines with a cockpit seating two people side by side, that likely were before their time.
