Yes, this is correct. The one in the first photo with the armmaments is what I call the British Military model. Bill Guthrie in Idaho had 2 that a guy here in Washington imported from england, along with a 3rd that he kept and 2 of the early Hagland/Volvo prototypes. The other Military rig that's much nicer is the NATO machine, and it had the spare track sections like a WW2 tank, a tall cab, the round pipe for a winch mount, front and rear, rear fenders, external fuel tank, fire exstingusher, shovel, knock down strobe light, real wing windows that open and was one single color of dark green.
The Early US Army ones were just like the civilian ones except that the upper cab was made of sheet brass instead of aluminum. Very early machines also had a teter toter arm roughly where the first shock goes and only one shock which was hooked to the second pair of bogey's. These machines all had the 36 Hp motor. The one in the flyer is probably one of these, putting it at 1957. A hunter in Alaska owns serial number 58, and it is somewhat original, with the shock arraingement as mentioned above, and a rebuilt 36 HP. Somewhere I have pictures of this machine. The owner had done a rather clever installation of a propane heater in the rear of the cab. A guy has one of the Brass cab's in North Pole and still takes it out once a year on hunts. The next to last dealer of snow tracs in alaska located the serial number 2 rig. It was at a fish processing facility in AK and was used to drag big fish nets up a ramp. Fish hooks in the tracks,pretty beat up, stank, but still ran as of 1994. It also would have been a brass cab. This would have been one of the original first machines that the US military purchased to "Try Out".