The story is totally confusing. I have never come across such an eccentric. The cast iron foundation of the drive is also installed in at least one plank machine.
https://www.ebay.de/itm/Dampfmaschine-von-PLANK-bespielt/324529726416?hash=item4b8f7aa3d0:g:WzQAAOSwWX1fqX9iDespite a great deal of competition, there has been a long-term collaboration between the Nuremberg manufacturers. The different manufacturers used the same parts in production. Maybe in this case too.
Hopefully someone in the forum will have one of the early dealer catalogs in which the machine is listed.