If you ever happened to go through Karlsruhe, Germany, there is a collection of mechanical transmission models from Redtenbacher. Some models were on display in the mechanical engineering building at the university.

I could only find this link (in German) about the collection. https://redtenbachersteyr.com/redtenbacher-in-karlsruhe/

One student from Redtenbacher was Reuleaux and there is another collection of transmission from Reuleaux at Cornell university. https://engineering.library.cornell.edu/kmoddl/