Jewelry & gold · a closer look
Johnson & Matthey mark: Johnson & Matthey, JM, JMI Assay Office
Mark details
- Maker
- Johnson & Matthey →
- Period
- Undated
- Wording
- Johnson & Matthey, JM, JMI Assay Office
Notes
"Johnson & Matthey", "JM", "JMI Assay Office"
Other Johnson & Matthey marks