So far, I have seen very few ceramic/china beads coming from Gablonz.
The ones I have seen are from the 1980's and quite crude, and have no relation to trade beads.

Sonneberg, near Lauscha could be an option, as this is a place with a history in making porcelain toys, and a connection (through Lauscha) with the export of trade beads.

Also France seems like an option. Then again, they could be African production too.