Gman, the bottom unbolts from the static body of that Bessey Combo, just like most others.---I was like you, I thought the static would just spin around and offset on the base, exposing bolt holes.
Yea, like Drive said, that site is TWERTSY'S brain child.---He has put untold hours in this treasure trove of info.---Want to be sure to give credit where credit is due.
Between Twertst's history site, and KMScott's web site on vise statistics, there's not much you can't uncover.
Hat's off to these fellows for starting these sites and everyone that helped them out and contributed to them.