The rare troppers you are looking for are either the RS troopers, or troopers that came with the offroad package.
The code on the build plate should be an S2J I believe. The RS troopers are two doors like the VX, but were only around in 89 and 93, with a handful in 94 and 95. I believe the RS troopers are just about, or rarer than a VX, so good luck.