Google.
http://en.wikipedia.org/wiki/Toyota_...281986-1992.29
http://www.japanesesportcars.com/supra/specs/
They do work. I just looked at them.
So your car is not "more Rare" you might have bought a Modifed one.
The Specs are accurate for the JDM specs.
You won't find American Specs for a JDM Car. Unless it's modifed then yes, you'll never find Specs for it because they don't exist.
I have no idea what you're talking about when you search for pictures and only find yours. You must be searching far too narrowly because I can find thousands of pictures of Supras USDM and JDM.
The Specs up there are accurate.