"Beads were not manufactured in Russia before the mid-18th century."

It is difficult to interpret the intent or scope of this remark. Does the writer mean "glass beads"—or any/all beads? There are published papers that purport glassmaking and beadmaking in Russia from earlier times. In one instance quite early (though this is a work that inspires my personal doubt). At the Danish Bead Conference (1992, I think), a paper was presented showing glass beads distinct to Russia. However, I don't think it was advanced (nor demonstrated) that the beads were MADE in Russia. But they were/are difficult to compare to other assemblages.

For the issue of "trade" and "trade houses," I recommend the essay posted at my Yahoo Group, Trade Bead Talk.