Dave,
Yes, it's extremely rare. The rear bodies are a mystery to us, they must have been made in Australia. This particular one has a longer wheelbase and extended rear frame which would make it an FJ28 I think. We never got them, there are pictures of few examples in Australia but I think that's it.
If you plan on restoring or preserving it (it should be) things that will make it easier for you if they are there will be:
1- transmission - 4 speed, non-synchro 1st and 2nd.
2- transfer case -single speed in-out 4WD with a band style parking brake on the output.
3- brakes - all cast iron master cylinders (no metal or plastic reservoirs)
4- axles - diffs are about 3" or so longer than a FJ40 diff.
5- Instrument Cluster - no oil or voltage gauges, idiot lights, silver background speedometer face.
6-Engine- everything is pretty much the same as the early 60's FJ40 F135 motor except the water temp and oil sender.
Even if it's a total piece of junk it's still worth picking up, maybe someone here would want you as a local contact.

If you could just get the VIN# from the data plate or front frame rail, curious what it begins with. For example a 1958 might be 8FJ25-1xxxx the 8 being the date of manufacture. FJ25 the model, don't know if the 25, 28 and other models had a different VIN#.
If you go look at it, pleeeeeeeeease take lots of pictures.

Just remember that rarity does not equal cash value when it comes to 25's.