I haven't really looked into it yet. Have these weights been checked or calibrated multiple times? I thought that was only done during production. I'll clean it better in the next few days and post new pictures.
Jan 26.1.2024
As far as I know, you can sometimes tell where it was calibrated based on the shape of the stamp and when it was calibrated based on the numbers (years). There may be a stamp from the manufacturer/location on the bottom or top of the weights. Since there is still room for more calibration stamps, you can theoretically determine the year of loss. If all three show a similar last calibration year, they probably went underground together.