You have to be very careful with that book. It is a photo
catalogue of someones
collection with their opinions. It is interesting, but frankly not well researched. Very very few of the identifications are backed up by references to archaeological sources. This is the difference in books by collectors and dealers that simply express opinions versus those that provide references to archaeological or academic works.
I am not trying to be critical. The same holds true for our site - many times we are only expressing opinions too.
But in some cases items are well documented.
For example, the exact
dish feet I was talking about are in that book as numbers 101-107. The book states they have no other practical use. In fact they are well know as
Roman dish feet and many have been found attached to the
Roman bronze dishes. They are well described in
Schleiermachen, M. "Die Romischen Fibeln von Kempten-Cambodunum" in Cambodunumforschungen V. (Kallmunz, 1993), which covers the metal finds from excavations at
Kempten (ancient Cambudunum).
As for yours, and their equivalents in that book - maybe they are in fact porto-money like the book says or maybe they a variant of the feet shown in 101-107. Uncertain without further references.
SC