{
  "illustration": "Deterministic instrument illustration, no historical specimen reconstruction",
  "top": {
    "rods": 11,
    "upper_per_rod": 2,
    "lower_per_rod": 5,
    "all_zero": true
  },
  "bottom": {
    "rods": 11,
    "upper_per_rod": 1,
    "lower_per_rod": 4,
    "all_zero": true
  },
  "bead_values": {
    "upper": 5,
    "lower": 1
  },
  "place_value_for_article": "decimal, adjacent rod ×10; hexadecimal only when explicitly assigned"
}