The last time I was there (a SOG event) were went into the back room to see the Kress Foundation Collection. There were frames 200-300 years old in the racks. Of most interest was a rather small frame made from real tortoise shell.
When I took a class from Jonathan Thorton, part of the class covered Dutch Ripple frames. Jonathan made a machine to make the rippled moulding. As a comparision we went to the Cleveland Art Museum Conservation lab were we saw sample of an old Dutch Ripple frame - a real Rembrandt was inside the frame and resting along the side wall was a Degas pastel ready for fitting.