26.8mm confirms CrMo tubing. Most likely a Tange set. Unfortunately, you can't tell if it is plain gauge or butted without a tubeset decal, as Tange used the same size seatpost for most of their tubesets.

600EX equipped bicycles are generally considered mid-range, which is where I would place the Shogun 1000. With Shogun, as the model numbers increase, so does the level. Offhand, I recall at leadt 3 models above the 1000. Later on, they switched to model names, making the hierarchy a little murkier, without knowing tubesets and components.