Not sure how the Albins were done so hopefully the interweb will help you find a fellow traveler. It is somewhat common the for stanchions, builders embed a tapped metal plate in the fiberglass and the stanchion uses a machine screw, no nut underneath. Others through bolt, others use thicker glass along there, others who-knows-what. You could try removing one and see what you get. Or removing some of the headliner in the salon below and having a look-see.
"There's the Right Way, the Wrong Way, and what some guy says he's gotten away with"