Considering the cost brand new, I'm not surprised no one has an
800S model Wilton, and according to this web page they now weigh 238 lbs. Probably had to make new molds (gee we made one twenty years ago, the molds must be here somewhere

) and they came out a little lighter.
Actually looking at the pictures of the tradesman vise models versus the machinist vise models, you don't actually see the differences. The machinist models must all be considerably longer and heavier built comparing the big difference in jaw openings and their weights.