This is the "Sneak Preview" brochure for the 1980 Liquifire was printed in the fall of 78 to help explain that there was no Liquifire for 79, and to build some anticipation for the 1980 Model Year.
The sled pictured hints of the new Liquifire, but seems a lot more "Trailfire-ish" by design. I think this sled may be a painted up Trailfire with a sport windshield and Liquifire decals. The seat and track look Trailfire, and there is no wheel kit in the skid either, but the specs discussed in the text describe the up and coming Liquifire pretty accurately.
After fielding a fuller line up in 78, including a 340 and 440 Cyclone, 340 Liquifires, limited build 340 Cross Country, 440 Liquifires and the 340 Spitfire, Deere dropped back to only 3 sleds for the 79 model year, a 340 and 440 Trailfire plus the 340 Spitfire. For 1980, Deere expanded the line up to 340 and 440 Trailfires, 440 Sportfire, 440 Liquifire and a 340 Spitfire, all Kawi powered for the first time.
In summary, it looks like there was no 1979 Liquifire by design. But this is written by an observer. Any thoughts from those that were there, or guys with better info would be very welcomed...
-Joe