I repaired one a bit back. The other sort with an embossed ply bottom. The scarf joint in the seat rim had come apart. Easy to take apart - it's all nuts, bolts, screws, except for two dowels through the scarf joint.
I mended the joint (glue, clamps, through dowels) but then hit a prob - I hadn't noticed that the ply edge was bevelled and fitted tight into a bevelled rebate in the rim. The rim must have been joined around the ply bottom in one go. So it was a boggar to get back in.
Lovely little chairs even though as common as house sparrows.
At about 1:30 mins into the video you can see the (modern) worker inserting a pre-woven cane seat into the chair. At the time the chair was originally produced, I think these chair seats would have been woven individually by hand. That's a pretty labour intensive process : I know from first hand experience - I have four Thonet chairs of another design under restoration, and to re-cane just one of the seats took me many hours work. I rather suspect this part of the job would have been subcontracted to cheap cottage labour.