Most of my tools around the house have minimal markings, if any. There are a zillion sizes of Allen key, and very few have the decency to mark themselves.

My measuring cups have markings are marked in paint, most of which has already worn away. Wouldn't stand a chance over millenia.

That said, you'd expect at least one or two to have informative notches for sizing. The universal dearth of text for such a common device is surprising.

And also, wouldn't they be a standard size for the region if they were for measuring coin? It sounds like each dodecahedron was different sizes.