Ancient bronze Roman and/or Celtic buttons collected in the Celtiberian region

A collection of seven ancient bronze buttons from a collection of Celtiberian artifacts (more on the provenance below). The buttons range in size, the smallest being 11mm (but possibly the most unique) and the largest being approx. 19 mm. The largest button has signs of enamel, especially along the inner ring's edges. The five others seem to follow a similar design pattern and sizing; there is one with protruding dots which seems like it might predate the others. They all seem to be made of bronze.

The buttons are mounted on paper, which is mounted to a piece of wood. Someone labelled the place locations where each is presumably from.

Provenance -
There are names written on many of the buttons, on the back, but without removing them I can't read them.

We bought a collection of artifacts at auction in Switzerland (La Galerie Numismatique, September 28th, 2024); we are researching each object and offering them for sale individually. You can see the collection in the pictures we posted.

In the course of our investigation, we found that the artifacts had names of places in the Celtiberian region written on them, for example "Salienca". Also, the larger brooch design was unique to the Celtiberians (Google search "Celtiberian Fibula" to see similar examples). We've come to the conclusion that the collection is specific to the Celtiberian era/region.

Wikipedia tells us the Celtiberians "were a group of Celts and Celticized peoples inhabiting an area in the central-northeastern Iberian Peninsula during the final centuries of the BC. They were explicitly mentioned as being Celts by several classic authors (e.g. Strabo)."

Condition -
See pictures. Some tarnish. Some bending. A few of the backs only have rotted away studs, while others still have loops.